N2O ionization and dissociation dynamics in intense femtosecond laser radiation, probed by systematic pulse length variation from 7 to 500 fs

We have made a series of measurements, as a function of pulse duration, of ionization and fragmentation of the asymmetric molecule N2O in intense femtosecond laser radiation. The pulse length was varied from 7 fs to 500 fs with intensity ranging from 4 × 10(15) to 2.5 × 10(14) W∕cm(2). Time and position sensitive detection allows us to observe all fragments in coincidence. By representing the final dissociation geometry with Dalitz plots, we can identify the underlying breakup dynamics. We observe for the first time that there are two stepwise dissociation pathways for N2O(3+): (1) N2O(3+) → N(+) + NO(2+) → N(+) + N(+) + O(+) and (2) N2O(3+) → N2 (2+) + O(+) → N(+) + N(+) + O(+) as well as one for N2O(4+) → N(2+) + NO(2+) → N(2+) + N(+) + O(+). The N2 (2+) stepwise channel is suppressed for longer pulse length, a phenomenon which we attribute to the influence which the structure of the 3+ potential has on the dissociating wave packet propagation. Finally, by observing the total kinetic energy released for each channel as a function of pulse duration, we show the increasing importance of charge resonance enhanced ionization for channels higher than 3+.

Residual Stress, Adhesion and Crystallization of Ion-Sputtered and Ibed Processed NiTi Films

When conventional sputtering is used to deposit nickel-titanium thin films at temperatures below ∼623 - 723 Kelvins, the resultant structures are amorphous and the films must be annealed to form the requisite B2 parent ordering. This invites complications related to interface diffusion and chemical reaction with components of the substrate. For the present work, thin films of near-equiatomic NiTi were prepared on potassium chloride, (100) single-crystal silicon, and Si3N4 passivated silicon substrates by ion sputtering and by ion beam enhanced deposition (IBED). We have investigated residual stress levels produced by these processes, evaluated substrate adhesion levels, and explored the crystallization behavior of NiTi films grown under conditions of concurrent low-energy inert gas ion bombardment. Residual stresses of ionsputtered and IBED films were measured using profilometric techniques. Film crystallization behavior was studied by transmission electron microscopy of as-deposited films. Films produced by unassisted ion sputtering showed compressive residual stresses in the as-deposited amorphous state, which became highly tensile after annealing, leading to spontaneous cracking and delamination. Preliminary results from IBED experiments showed a reduction in the asdeposited stress, and improved adhesion. Under certain conditions, ion enhancement of the deposition process promoted film crystallization during deposition at moderate substrate temperature, producing a dispersion of extremely fine particles, indexed as Ni3Ti.

Ultrasound examination in twin pregnancy and late fetal death

OBJECTIVE

To test the hypothesis that the (case) twin later to succumb in utero has biparietal diameter measurements (by ultrasound) different from those (control) twins surviving the perinatal period.

MATERIAL AND METHODS

Information from the Medical Birth Registry, National Board of Health and Welfare, Stockholm, was used to identify all births in a defined population in southern Sweden with about 20,000 deliveries each year. In 3,019 twin pregnancies between 1973 and 1989, one or both twins were stillborn in 47 cases (gestational duration > or = 28 weeks, birthweight > or = 500 g). For each case pregnancy, two control pregnancies were selected, the matching criteria being: same delivery unit, same parity (0, I, II, III+), similar year of delivery (+/- 1 year) and maternal age (+/- 5 years). Data on ultrasound examinations were extracted from the original medical records. Screening in early second trimester started at one of the units as early as 1973 and at the latest of 12 units in 1982.

RESULTS

There was no obvious difference between cases and controls in intra-pair discordant biparietal diameter (BPD) measured in early second trimester. Nor was there any evident difference in the rate of deviant BPD between cases and controls. In all, 8% of dead male and 24% of dead female fetuses were by definition small-for-gestational age (< -2 standard deviations).

CONCLUSIONS

No significant difference was seen between cases and controls regarding deviating biparietal diameters. Abdominal diameter may be a better predictor of subsequent fetal death (not analysed in this study), though only about 15% of all dead twins were deemed small-for-gestational age.

Lack of correlation between maternal body weight or weight gain and stillbirth in twin pregnancy

OBJECTIVE

To study differences in maternal weight and weight gain for 48 twin-pregnant women with at least one stillbirth, versus 96 control mothers where both twin pairs survived the perinatal period.

MATERIAL AND METHODS

In all, 48 twin gestations with one or both twins dead before or during birth (cases), in a defined region with 12 hospitals in southern Sweden between 1973 and 1989, were identified by using information stored at the Medical Birth Registry, the National Board of Health and Welfare, Stockholm. For each case pregnancy, two control twin pregnancies were selected; matching criteria were same parity and delivery unit, and similar year of delivery (+/- 1 year) and maternal age (+/- 5 years).

RESULTS

Case and control women had a similar number of maternal body weight measurements during pregnancy, 8.9 vs. 8.0 (t = 1.5, p > 0.05). No significant difference between cases and controls was found regarding maternal weight (mean +/- SEM) at 12 weeks of gestation (68.0 +/- 1.4 vs. 68.1 +/- 0.9 kg; t = 0.2, p > 0.05), or in weight gain/pregnancy week (0.59 +/- 0.28 vs. 0.61 +/- 0.19 kg; t = 0.8; p > 0.05).

CONCLUSION

The results of this study indicate that repeated body weight measurements of the twin-pregnant woman are of very limited value in the identification of a twin-pregnant woman later to face stillbirth.

Maternal health care program and markers for late fetal death

OBJECTIVE

To identify markers for late fetal death, a multicenter study was performed, based on routinely obtained data from maternal health care units.

MATERIAL AND METHODS

Prospectively recorded data were obtained from maternal health care units belonging to five delivery units. In all, 233 consecutive cases of singleton pregnancy involving late fetal death (> or = 28 weeks) were identified between 1983 and 1989. As a control for each case, the next consecutive mother giving birth to a live infant at the same delivery unit was selected, the sole matching criterium being parity.

RESULTS

After exclusion of pregnancies with lethal malformations or trauma, 205 cases remained for the statistical analysis. Two main subgroups were identified: mothers with placental abruption (n = 44), and pregnancies with no obvious reason for fetal death (n = 101). An increased risk for late fetal death was evident in expectant mothers > or = 40 years (10 vs 1; chi 2 = 7.6, p < 0.01), and in smokers where an association was seen to placental abruption. A significantly increased risk was also seen in women with medical treatment for essential hypertension (8 vs 1; chi 2 = 5.6, p < 0.05). On the other hand, we found no correlation between proteinuria, glucosuria, decreasing symphysis-fundal height, or changes in the Hb, on the one hand, and late fetal demise, on the other. There was no overrepresentation of post dated pregnancy (by ultrasound early in the second trimester) among the cases. Nor did post dated pregnancies (> or = 42 weeks) estimated from first day of last menstrual period (but not post dated by ultrasound) imply a higher rate of fetal death, as has been suggested in previous studies.

CONCLUSION

In the present material, there was no sign of systematic error in the evaluation of data routinely obtained from the antenatal clinics and maternity units. Apart from placental abruption in smokers, a high maternal age, and medical treatment for essential hypertension, deviating data were recorded as often among controls as among cases. No correlation was evident between a post date pregnancy and fetal demise. A short symphysis-fundal height was recorded as often among controls as among cases and the even distribution of fetal birthweight in case pregnancies around the standard curve for the normal population is noteworthy.

No relation between maternal weight gain and stillbirth

BACKGROUND

To evaluate the relationship between stillbirth in singleton pregnancy (> or = 28 weeks gestation) and maternal weight (weight gain) from 24 completed weeks.

METHODS

All fetal deaths (n = 210) at five delivery units during seven years in southern Sweden were analysed. To each case a control mother was selected, the only matching criteria being parity and place of delivery. Regression analysis was used for comparison of body weight gain in cases and controls.

RESULTS

Mothers experiencing stillbirth had a significantly lower mean body weight at 24 weeks gestation than control mothers (63.5 kg vs 67.3 kg; t = 2.4, p < 0.05). No significant difference between cases and controls was found in mean weight gain during pregnancy from 24 completed gestational weeks to delivery, even when the last three measurements before delivery for cases and controls were compared separately.

CONCLUSION

There is no difference in body weight gain between mothers with stillbirth and mothers giving birth to a live infant.

Effects of oophorectomy, sympathetic denervation and sex steroids on uterine norepinephrine content and myometrial contractile response to norepinephrine in the guinea pig

Studies were performed in guinea pigs to elucidate alterations in endogenous uterine norepinephrine (NE) levels and changes in the contractile response to exogenous NE following local sympathetic denervation, oophorectomy, or treatment with sex steroids. Both in intact and oophorectomized animals the myometrial NE concentration was reduced after sex steroid treatment (0.5 microgram 17-beta-estradiol, or 0.1 microgram estradiol plus 2 mg progesterone, during 2 weeks), mainly as a result of increased uterine weight. After surgical removal of the hypogastric nerves and section of the suspensory ligaments, a similar response to sex steroids was seen if the animals had previously been oophorectomized. The myometrial contractile activity induced by exogenous NE was measured in vitro. The EC50 values (NE concentration giving 50% of the maximal response) showed a similar pattern of variations after hormonal treatment and oophorectomy as did the concentration of endogenous NE. Thus, exposure to the steroids leading to a reduction of neuronal NE also caused an increased sensitivity of the myometrial smooth musculature to exogenous NE, and in the various experimental groups the two parameters showed a close and significant relationship. The underlying mechanism may induce a denervation supersensitivity to NE induced by exposure to estrogen and progesterone.

Immunocytochemical demonstration of contractile cells in the human ovarian follicle

Actin- and myosin-like immunoreactivity is found in cells located in the theca externa of the follicle wall of the human ovary, and corresponding to previously observed myoid cells. The immunocytochemical observation provides direct structural evidence that non-vascular contractile cells are also present in the follicle wall in humans. As expected, perifollicular blood vessels showed a positive immunoreaction for actin and myosin in their smooth muscle walls.

Myometrial norepinephrine in human pregnancy. Elevated levels in various disorders leading to cesarean section

Myometrial norepinephrine was measured consecutively with high-performance liquid chromatography in women who delivered by cesarean section. The previously recorded marked reduction in tissue norepinephrine at the end of normal pregnancy was confirmed. When cesarean section was performed because of abruptio placentae/hemorrhage, impending asphyxia, dystocia or preeclampsia, the norepinephrine concentrations were six to ten times higher than in normal pregnancy. When an emergency cesarean section was carried out for premature breech presentation, transverse position of the fetus or prolapse of the umbilical cord (following an otherwise-normal pregnancy), the reduced norepinephrine values were not significantly different from those measured in a control group of women who underwent elective cesarean section. It is possible that the abnormally elevated levels of myometrial norepinephrine are part of the primary pathophysiologic condition associated with sympathetic overactivity, resulting in disturbed myometrial circulation and/or motor activity.

Extracellular and intracellular calcium sources mediating contractile responses of smooth muscle in bovine ovarian follicle and ovarian artery

The relative importance of extracellular and intracellular calcium sources mediating smooth muscle contraction in ovarian follicle and ovarian artery was assessed in experiments on the influence of nifedipine, D-600, amrinone, diethylstilbestrol (DES), lanthanum and/or calcium removal on contractions induced by K+ depolarization, by noradrenaline, histamine and acetylcholine. The K+-induced response was biphasic in the ovarian artery but not in the ovarian follicle. The K+-induced contraction in both preparations was greatly inhibited by nifedipine (1 microM), D-600 (10 microM) and lanthanum (2 mM). Although both phases of the responses in the ovarian artery appeared to be completely dependent on extracellular calcium, phase I was significantly more sensitive to nifedipine than phase II. Incubation in calcium-free medium for 15 min almost abolished the K+-induced contraction. Noradrenaline- and histamine-induced contractions of ovarian follicle were essentially unaffected by nifedipine (1 microM) and D-600 (10 microM) whereas the noradrenaline-induced contraction in ovarian artery was inhibited significantly by D-600 (1 and 10 microM) but not nifedipine (1 microM). In calcium-free medium containing EGTA (1 mM) the responses of ovarian follicle to noradrenaline and histamine were reduced by 26 and 22% respectively. When preparations were stimulated with noradrenaline more than one in calcium-free medium, the contraction decreased progressively compared to time-matched controls. The response was 34% of the control after 50 min in calcium-free medium containing EGTA. In the ovarian artery the response obtained (6% of control) was significantly smaller (P less than 0.05) than that in the follicle.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of histamine receptors mediating contraction and relaxation of the ovarian follicle wall

Histamine is known to be present in ovarian tissue and may play a role in the ovulation process. The effect of histamine on the follicular smooth musculature was investigated using strips from the protruding part of mature bovine follicles, mounted in vitro for registration of isometric motor activity. Histamine contracted the preparation in a concentration-dependent manner. The response was inhibited competitively by the specific H1 receptor antagonist pyrilamine while the adrenergic alpha-receptor antagonist phentolamine had no clear-cut effect. A Schild plot revealed a pA2 value of 8.81, corresponding to a mean KB value (dissociation constant for receptor-antagonist complex) of (7.5 +/- 3.2) X 10(-9) M. After potassium depolarization and blockade of the contractile H1-receptors with pyrilamine, histamine induced a concentration-dependent relaxation of the follicle wall preparation. This response could be inhibited by the H2-receptor antagonist cimetidine (which also potentiated the contractile effect in the absence of pyrilamine). The pA2 value for the cimetidine-induced inhibition was 6.25, and KB was found to be (6.5 +/- 3.0) X 10(-7) M. The beta-receptor antagonist propranolol was effective only in very high concentrations. It is suggested that a possible role for histamine during follicle rupture is mediated via specific receptors in the follicular smooth musculature.

The influence of prostaglandin E2 and indomethacin on progesterone production and ovulation in the rabbit ovary perfused in vitro

The effects of prostaglandin E2 (PGE2) on the ovulation process were studied in a recirculating perfusion model using ovaries from virgin rabbits. Ovulation frequency, time of ovulation, and progesterone release from the ovaries were examined after the addition of PGE2, either alone or with luteinizing hormone (LH) in the presence or absence of indomethacin. The stimulatory effect of LH on ovulation was totally blocked if the ovaries were exposed to indomethacin at the same time. Ovaries treated with PGE2 alone did not ovulate, and PGE2 was unable to restore indomethacin-blocked ovulation. Conversely, the frequency of ovulation was reduced in ovaries treated with PGE2 and LH compared with controls receiving only LH. There was no measurable difference in the pattern of progesterone release between ovaries simultaneously treated with LH and indomethacin and LH-treated controls. Ovaries exposed to PGE2 alone showed only a slight increase of progesterone release in the medium, while those treated with PGE2 in combination with LH in the perfusate showed a smaller progesterone release than those treated with LH alone. The results confirm the blocking effect on ovulation by indomethacin. PGE2 could not reverse this effect, but instead reduced the number of LH-induced follicular ruptures. Indomethacin had no effect on progesterone levels, while PGE2 (which alone showed a slight stimulating effect on the steroid concentration) together with LH counteracted the effect of LH on progesterone release.

Evidence for prejunctional GABAB receptors mediating inhibition of ovarian follicle contraction induced by nerve stimulation

The motor effects of gamma-aminobutyric acid (GABA) on the bovine ovarian follicle were studied in vitro using strips from follicle walls. Electrical field stimulation of nerves in the preparation, secured by tetrodotoxin blockade, caused a contraction that was almost totally abolished by phentolamine and only slightly affected by atropine. This mainly adrenergic neurogenic response was inhibited by GABA in a dose-dependent way. The GABAA-receptor antagonists, bicuculline and picrotoxin, did not affect the GABA action whereas the GABAB-receptor antagonist, homotaurine, significantly inhibited the GABA effect. The GABAA-receptor agonist, muscimol, did not affect the contractile response while the GABAB-receptor agonist, baclofen, imitated the action of GABA. On the other hand, GABA had no direct contractile or relaxing effect on the follicle strips nor did it interfere with the contractile response induced by noradrenaline or acetylcholine. The findings suggest that activation of prejunctional GABAB receptors inhibits transmitter release from mainly adrenergic nerves associated with the follicle, thereby affecting nerve-mediated tension in the follicle wall.

Evidence for a role of prostaglandins in the adrenergic neuromuscular mechanism of the ovarian follicle wall

Sympathetic nerves innervate smooth muscle cells in the theca externa of Graafian follicles and induce contraction of the follicle wall. The interaction of prostaglandins (PGs) with the function of this neuromuscular complex has been elucidated by the use of isolated strips from the protruding part of the wall of bovine ovarian follicles. PGF2 alpha contracts the strips, and it also potentiates the contractile response to electrical field stimulation of the nerves, but it has no effect on noradrenaline-induced contractions. PGE1 and PGE2 have direct relaxatory actions on the strip preparation (previously given an active contraction by carbamylcholine) and in high doses they, therefore, reduce the contractile response induced by noradrenaline. In low doses not affecting the noradrenaline response, PGE1 and PGE2 both decrease the amount of contraction induced by electric nerve stimulation, indicating an inhibitory action of the PGEs on the transmitter release. It is suggested that the role of PGs in the process of ovulation might, at least partly, be mediated by their interactions with smooth muscle cells and their sympathetic innervation in the wall of the Graafian follicle.

Existence and coexistence of peptides in nerves of the mammalian ovary and oviduct demonstrated by immunocytochemistry

The immunocytochemical distribution of substance P (SP), gastrin releasing peptide (GRP), vasoactive intestinal polypeptide (VIP), peptide histidine isoleucine (PHI), and neuropeptide Y (NPY) was studied in the ovary and the Fallopian tube (oviduct) of rats, guinea-pigs, cows, pigs and humans. Generally, the nerve supply was better developed in the oviduct than in the ovary. GRP fibers were most scarce in all tissues. Nerves containing SP were particularly numerous in the oviduct of rat and guinea-pig, supplying the muscular wall and blood vessels. VIP and PHI coexisted in dense plexuses of nerves, not only around blood vessels but also in the follicular wall and the interstitial gland of the ovary, as well as within the smooth muscle layers and subepithelially in the oviduct. The general distribution of NPY was similar, but these immunoreactive nerves were even more numerous. Sequential staining for dopamine-beta-hydroxylase and NPY together with results of chemical sympathectomy with 6-hydroxydopamine suggested that NPY was stored in the noradrenergic sympathetic nerves.

Involvement of local adrenergic receptors in the process of ovulation in gonadotrophin-primed immature rats

Immature female rats were primed with 4 i.u. PMSG at 08:00 h of Day 26. This results in ovulation in the morning of Day 29. The number of ovulations was counted in terms of newly formed corpora lutea in the morning of Day 30. Various adrenergic drugs were delivered into the ovarian bursa bilaterally in the afternoon of Day 27 to study their effect on ovulation. A methyl cellulose gel solution was used as vehicle to minimize leakage from the bursa. Noradrenaline, terbutaline and 4-aminopyridine significantly enhanced the number of corpora lutea compared to control ovaries injected with gel vehicle alone. The effect of terbutaline was counteracted by propranolol. Phentolamine partly blocked the noradrenaline-induced enhancement and the antagonist alone significantly reduced the number of ovulations. The results indicate that stimulation of alpha-adrenergic receptors (probably via actions in the follicle wall) as well as beta-receptors (influencing steroid-producing cells) may interfere with the ovulation process.

Changes in oviductal VIP content induced by sex steroids and inhibitory effect of VIP on spontaneous oviductal contractility

The content of vasoactive intestinal polypeptide (VIP) in rabbit oviducts was determined using a radioimmunoassay technique. Treatment with oestrogen (polyestradiolphosphate) alone for 5 days caused a significant increase in oviductal VIP content, whereas addition of progesterone during the last 3 days of an 8 day polyestradiol-phosphate treatment resulted in a return of VIP content to control levels. The effect of VIP on oviductal smooth muscle contractility was investigated using an in vitro system. It was found that VIP caused a reduction of spontaneous contractile activity in doses as low as 10(-10) M and this reduction in motor activity was strictly dose dependent with an ED50 value similar to that reported for the VIP activity on rabbit myometrial smooth musculature.

Influence of adrenoreceptor agonists and antagonists on ovulation in the rabbit ovary perfused in vitro

Ovaries from sexually mature virgin rabbits were dissected free on both sides and cannulated in situ via that part of the aortic segment supplying the ovarian arteries. The ovaries were mounted in a closed, recirculating perfusion system for oxygenation in vitro. Ovulation was induced by human chorionic gonadotropin (hCG) given either i.v. (100 IU) or directly into the perfusion medium (20 IU). Follicular ruptures occurred in 42 out of a total of 54 ovaries. The in vivo route of hCG administration was found to be most efficient, with ovulations occurring after a mean of 11.5 h, which corresponds well with the incidence of ovulations in situ. The prostaglandin synthesis inhibitor, indomethacin, totally abolished the hCG-induced ovulations. beta-Adrenoreceptor stimulation in vitro with terbutaline or with noradrenaline in the presence of alpha-receptor blockade with phenoxybenzamine caused a significantly increased number of gonadotropin-induced ovulations. Phentolamine or phenoxybenzamine given alone reduced the number of ruptured follicles. Noradrenaline (in the absence of hCG) and clonidine augmented the incidence of ovulation. The results indicate that local adrenoreceptor mechanisms participate in the process of ovulation, both via alpha-adrenoreceptors (probably affecting the follicular smooth musculature) and beta-adrenoreceptors (possibly through some trophic or endocrine mechanism other than a mechanical factor).

Histochemistry and ultrastructure of adrenergic and acetylcholinesterase-containing nerves supplying follicles and endocrine cells in the guinea-pig ovary

The autonomic nerve supply of the guinea-pig ovary was investigated by a combination of light- and electron microscopy. At the light-microscopic level, adrenergic fibres were identified due to their formaldehyde-induced fluorescence. In addition, the ovary contained acetylcholinesterase-positive fibres. In all parts of the ovary, the adrenergic fibres were most numerous. At the ultrastructural level it was possible to identify the adrenergic nerve terminals with the aid of the false adrenergic transmitter, 5-hydroxy-dopamine. Thus, large numbers of adrenergic terminals, characterized by their content of 50-60 nm, electron-dense synaptic vesicles, were seen within the interstitial gland, where they formed close contacts with the endocrine cells (membrane-to-membrane distance, 20-100 nm). The follicular theca externa was also richly supplied by adrenergic nerves. At this location, close contacts (50-100 nm) were identified between the nerve terminals and the smooth muscle-like cells. Very few adrenergic nerve fibres were present in the theca interna of follicles or in the corpus luteum. Non-adrenergic nerve terminals, characterized by electron-lucent synaptic vesicles of 50-60 nm diameter, were observed together with the adrenergic fibres. They were always present in much lower numbers than the latter. No "p-type" nerves were identified by electron microscopy.

Intraovarian adrenergic nerves in the guinea-pig: development from fetal life to sexual maturity

The development of the intraovarian adrenergic nervous system was investigated in the guinea-pig by use of chemical determination of catecholamines with high performance liquid chromatography (HPLC) and with the formaldehyde-induced fluorescence method for visualization of adrenergic nerves (Falck-Hillarp technique). Ovaries from fetuses (39-40, 45-50, 55-57, 60-63 days of gestation) and young animals (1, 2, 3, 7, 14, 30, 40-45 days of age) were included in the study. The noradrenaline concentration was low in the ovaries from the youngest fetuses but increased with age, reaching a maximum level at 2 days post partum. A marked decrease in noradrenaline concentration from the second to the third day of life was found as a consequence of the rapid increase in the ovarian weight during this time. A similar decrease in ovarian noradrenaline concentration after a period of rapid ovarian growth was noted at 30 days of age. Measurable amounts of adrenaline were found in the ovary only in the fetal stages; the highest concentration (0.73 microgram) was detected at 55-57 days of gestation.

Electron microscopic and pharmacologic evidence for a functional adrenergic innervation of the smooth musculature in the human fallopian tube

Triple fixation for electron microscopy of the isthmic region of the human Fallopian tube distinguished adrenergic nerve terminals through their content of synaptic vesicles with a diameter of 50-60 nm. Non-vascular adrenergic nerves were found both outside and within smooth muscle bundles. Adrenergic varicosities, partly devoid of their Schwann cell ensheathing, frequently approached the smooth muscle cells within a distance of about 200 nm, and sometimes as close as 60-100 nm. These close contacts often occupied a considerable area of the naked varicosity. Electrical field stimulation of adrenergic nerves in the isthmic smooth muscle preparations in vitro induced an alpha-receptor mediated, frequency-dependent contractile response. The results show that the sympathetic nerves in the human Fallopian tube are able to exert a motor control of its smooth musculature, and may thus be involved in local functions essential for the normal fertilization process.

Contraction of the ovarian follicle induced by local stimulation of its sympathetic nerves

Strips of bovine ovarian follicle wall, known to contain smooth muscle cells innervated by adrenergic nerves, were dissected out and exposed to transmural electrical stimulation in an organ bath. A frequency-dependent contractile response was obtained with a maximum at 8-16 Hz. The response was abolished in the presence of tetrodotoxin and inhibited by bretylium, phentolamine and reserpine. Thus, stimulation of the sympathetic nerves in the ovarian follicle releases sufficient amounts of norepinephrine to produce a contraction of its wall, an effect mediated by alpha-adrenergic receptors.

Quantitative pharmacological characterization of beta-receptors and two types of alpha-receptors mediating sympathomimetic smooth muscle response in the human Fallopian tube at various cyclic stages

The dissociation constants for adrenoceptor-antagonist complexes (KB) were determined in vitro in circular and longitudinal smooth musculature from the ampullary and isthmic regions of the human Fallopian tube. High extracellular potassium concentrations were used to eliminate the spontaneous contractile activity. Neuronal and extraneuronal amine uptake mechanisms were blocked. The parallel shift of the log dose-response curves was secured in Arunlakshana-Schild plots. KB for the beta-receptor, mediating sympathomimetic relaxation, were determined during alpha-receptor blockade: the values for propranolol were the same (approximately 10(-6) M) in all preparations and at all cyclic stages, as determined from plasma estradiol and progesterone levels. KB for the complex between the alpha-receptor (mediating contraction) and phentolamine were determined during beta-receptor blockade. The values were the same in all types of smooth musculature, but varied with cyclic stage: they were around 7 x 10(-8) M when plasma estradiol and progesterone were both minimum, and around 2 x 10(-7) M when these steroid levels were moderate to high, suggesting that the properties of the contractile receptors of the human Fallopian tube are modified during the menstrual cycle.

Motor activity of the human Fallopian tube in vitro in relation to plasma concentration of oestradiol and progesterone, and the influence of noradrenaline

The contractile pattern of the human Fallopian tube was studied in preparations from the ampullary and isthmic regions mounted in an organ bath for measurement of longitudinal and circular smooth muscle activity. The material was obtained during the follicular, ovulatory, and luteal phases of the cycle as defined primarily from plasma oestrogen and progesterone values. The frequency of the spontaneous contractions increased progressively during the follicular phase to become maximal around ovulation. There was no consistent difference between isthmus and ampulla; the circular musculature had a higher frequency than the longitudinal during the ovulatory phase. Noradrenaline (3 x 10(-6) M) in general potentiated the difference in frequency seen between the ovulatory phase on the one hand and the follicular and luteal phases on the other. Contractile activity, assessed by planimetric integration of the curve on the pen-recorder trace, increased markedly during the ovulatory phase in all types of smooth muscle preparations. Exogenous noradrenaline inhibited spontaneous motor activity in preparations from pregnant or post-menopausal women or from women taking combined-type oral contraceptives. This effect was most marked in the circular muscle. Thus the different regions of the human Fallopian tube in vitro show various patterns of spontaneous motor activity in relation to the plasma steroid concentrations furing the menstrual cycle. Responses to exogenous noradrenaline also varied, indicating that the effects of endogenous noradrenaline released from sympathetic nerves may vary similarly.

Comparative study of the autonomic innervation of the mammalian ovary, with particular regard to the follicular system

The autonomic innervation of the ovary was studied in 12 mammalian species utilizing the cholinesterase method in combination with pseudocholinesterase inhibition for the cholinergic component, and glyoxylic acid histochemistry together with fluorometric determination of noradrenaline for the adrenergic component. Ovaries from cow, sheep, cat, and guinea pig were very richly supplied with adrenergic nerves in the cortical stroma, particularly enclosing follicles in various stages of development. In the follicular wall the nerve terminals were located in the theca externa, where they ran parallel to the follicular surface. Numerous adrenergic terminals also surrounded ovarian blood vessels. The adrenergic innervation was of intermediary density in the human ovary and in the pig, dog, cat, and opossum. Ovaries from rabbit, mouse and hamster had a sparse adrenergic nerve supply. The amount of intraovarian adrenergic nerves agreed well with the tissue concentration of noradrenaline in the various species. The cholinergic innervation was generally less well developed, but had the same distribution as the adrenergic system around blood vessels and in the ovarian stroma, including follicular walls.

Relaxation of human female genital sphincters by the neuropeptide vasoactive intestinal polypeptide

Vasoactive intestinal polypeptide (VIP), a recently recognized neuropeptide with a putative transmitter function, has been demonstrated in nerves in the female genital tract. The highest density is in the smooth, muscle of the isthmus of the fallopian tubes and of the uterine cervix. The motor effect of VIP has been tested in vitro of smooth muscle from the isthmus and the uterine cervix. Both preparations responded to VIP with a concentration-dependent reduction in motor activity.

Female sex steroid concentrations in the ampullary and isthmic regions of the human fallopian tube and their relationship to plasma concentrations during the menstrual cycle

The concentrations of estradiol-17 beta (E2) and progesterone (P) were measured in the ampullary and isthmic portions of the fallopian tube of nonpregnant menstruating women and the cyclic fluctuations were related to the concentrations of these hormones in plasma. The steroid concentrations were determined by radioimmunoassays. There was no significant difference in the isthmic and ampullary concentrations of either steroid in any of the menstrual phases. The mean value for E2 was highest in the ovulatory phase and for P during the luteal phase. The tissue (per gm)/plasma (per ml) ratio for the steroid concentrations was above unity in all measurements. The ratio for E2 was highest (isthmus:12, ampulla:8) in the follicular phase and for P (isthmus:26, ampulla:18) during ovulation. Since these highest ratios were attained when plasma steroid concentrations were relatively low they were interpreted as reflections of a maximal receptor contribution.

Peptidergic (enkephalin) innervation of the mammalian esophagus

Enkephalin-like immunoreactivity was demonstrated in nerves in the esophagus of guinea-pig, opossum, cat, pig, monkey, and humans. Immunoreactive nerves were found in the external muscle layer and in the muscularis mucosae. In the myenteric plexus immunoreactive nerve fibers were numerous; immunoreactive nerve cell bodies were observed only occassionally. Enkephalin nerves appeared early (the 7th wk of gestation) in porcine fetuses; at this stage the nerves were confined to the myenteric plexus. Motor effects of enkephalin were studied on segments from circular smooth muscle of cat esophagus. Enkephalin inhibited electrically induced contractions in a dose-dependent manner. This effect was blocked by naloxone. The results suggest that enkephalin nerves may be involved in the regulation of esophageal motility. Like enkephalin, bretylium (a blocker of adrenergic transmission) and phentolamine (on alpha-adrenergic blocker) prevented the contractile response to electrical stimulation. With smooth muscle strips from reserpinized cats the response to electrical field stimulation was abolished, but not the response to norepinephrine. Taken together, the results suggest that neuronal enkephalin in the esophagus functions as a modulator of adrenergic transmission.

Origin and distribution of VIP (vasoactive intestinal polypeptide)-nerves in the genito-urinary tract

VIP (Vasoactive Intestinal Polypeptide)-immunoreactive nerves were found throughout the genito-urinary tract of the cat; they were less numerous in the guinea pig and in the rat. In the cat, VIP nerves were particularly numerous in the neck of the urinary bladder and proximal urethra, in the uterine cervix and in the prostate gland. The nerves were found in smooth muscle, around blood vessels and in the connective tissue immediately beneath the epithelium. Ganglia were found below the trigonum area of the bladder, in the wall of the proximal urethra, and in paracervical tissue. VIP-immunoreactive nerve cell bodies occurred in all these ganglionic formations. These ganglia probably represent the origin of the VIP nerves of the genital tract since their removal in the female cat greatly reduced the VIP nerve supply. Transection of the hypogastric nerves had no overt effect. Transection of the cervix eliminated the VIP nerves above the level of the lesion, except those in the ovaries, supporting the view that the VIP nerves of the uterus and the oviduct are derived from a paracervical source.

Application of the aluminum-formaldehyde (ALFA) histofluorescence method for demonstration of peripheral stores of catecholamines and indolamines in freeze-dried paraffin-embedded tissue, cryostat sections and whole-mounts

This paper describes new procedures for highly sensitive visualization of monoamine stores in peripheral tissues, taking advantage of the recently introduced aluminum-catalysed formaldehyde (ALFA) reaction. The tissues are exposed to an aluminum sulphate solution (with or without formaldehyde fixation) in a perfusion and/or immersion step, followed by formaldehyde vapour treatment. Procedures are described for freeze-dried, paraffin embedded tissue, cryostat sections and whole mount preparations. For all these tissue preparations the ALFA method gives a highly sensitive and precise demonstration of catecholamine-containing neurons and 5-HT-containing cells in a variety of peripheral tissues. For freeze-dried tissue and cryostat sections the ALFA method represents an improvement in comparison with other available methods. This is particularly noticeable for the very delicate adrenergic nerves in such organs as the thyroid, ovary, pancreas and the gastrointestinal tract.

Fluorescence histochemical demonstration of a relationship between adrenergic nerves and cells containing actin and myosin in the rat ovary, with special reference to the follicle wall

Contractile proteins (actin and myosin detected by immunohistochemistry) were present in elongated cells forming concentric layers in the theca externa of Graafian follicles and around corpora lutea. Immunofluorescent cells were also found in the ovarian stroma. Study of adrenergic nerve fibres by the glyoxylic acid technique showed numerous branches in between and in close association with the contractile cells.

Functional role of an adrenergic sphincter in the female urethra of the guinea-pig

By means of a microtransducer catheter, the urethral pressure profile was recorded in female guinea-pigs. The maximum urethral pressure averaged 24 mmHg (range 18-27 mmHg) and was found 4 to 7 mm from the vesico-urethral junction. Fluorescence microscopy of the urethra showed an irregular distribution of fluorescent nerve terminals in the most proximal part of the organ. In a distal direction, there was a continuous increase in the number of adrenergic nerves, with a maximum 4 to 6 mm from the internal meatus, corresponding to the maximum intraurethral pressure point. In this region, a dense plexus of nerves supplied thick muscle coats of smooth muscle having an outer circular and an inner longitudinal orientation. The findings suggest that a specific region of the female guinea-pig urethra may serve as an "internal sphincter".

Cyclic fluctuation in noradrenaline transmitter of the monkey oviduct

Cyclic variations in noradrenaline of the sympathetic nerves ("short adrenergic neurons") innervating the smooth musculature of the oviduct have been determined by fluorescence histochemistry and fluorometric measurements in monkeys (Macaca mulatta). During the secretory phase there is more than twice as much neuronal noradrenaline in the oviduct compared with the proliferative phase. This suggests, that the system of adrenergic nerves in the primate oviduct is involved in the motility changes associated with alterations in the level of endogenous estrogen and progesterone during the menstrual cycle.

Neuronal localization of pancreatic polypeptide (PP) and vasoactive intestinal peptide (VIP) immunoreactivity in the earthworm (Lumbricus terrestris)

Nerve fibres and cell bodies displaying vasoactive intestinal polypeptide (VIP) or pancreatic polypeptide (PP) immunoreactivity were demonstrated in ganglia of the earthworm (Lumbricus terrestris). VIP cell bodies were found in the most anterior ganglion of the ventral nerve cord, the subpharyngeal ganglion. Immunoreactive nerves were seen running in the center of the cord until about the 10th segment. PP cell bodies were found in the cerebral ganglion where VIP was lacking, in the subpharyngeal ganglion and in more posteriorly located ganglia of the ventral nerve cord. PP nerve fibres could be followed below the 10th segment of the cord.

Mechanical response in the wall of ovarian follicles mediated by adrenergic receptors

The identity of the adrenergic receptors involved in the contractility of the follicular wall was studied in bovine ovaries. Strips were prepared mainly from the protruding part of large Graafian follicles and mounted in an organ bath for recording of mechanical activity. Some intact ovaries and strips from the bottom of follicles were also studied. The latter two preparations showed spontaneous rhythmic contractions, and the tension was increased by norepinephrine and reduced by terbutaline. Norepinephrine, epinephrine, phenylephrine, isoproterenol and terbutaline alone or in combination with various concentrations of the inhibitors, phenoxybenzamine, piperoxan and propranolol, were used to analyze adrenoceptors in strips from the protruding portion of the follicle. Such strips showed no appreciable spontaneous contractions. A contractile response was found to be mediated by alpha receptors. The KA value for norepinephrine (determined in combination with phenoxybenzamine) was found to be 2.26 X 10- minus 6 M and KB for piperoxan (determined in combination with norepinephrine) was 1.02 X 10-minus 8 M (pA2 = 8.19). Adrenergic beta receptors mediated relaxation of the strips, and the KB value for propranolol (determined in combination with terbutaline) was 7.28 X 10-minus 9 M (pA2 = 8.17).

Ultrastructural evidence for adrenergic innervation of the interstitial gland in the guinea pig ovary

Fluorescence microscopy has shown that the guinea pig ovary contains not only vasomotor adrenergic nerves but also many nerve terminals running within endocrine structures. Electron microscopy of the interstitial gland confirmed the presence of adrenergic nerves distinguished by administration of the false transmitter, 5-hydroxydropamine. Axon varicosities, denuded of their Schwann cell ensheathing, innervated the endocrine cells in the interstitial gland, with a synaptic distance of approximately 400 A. This suggests that the interstitial gland participates in a neuroendocrine transducer mechanism.

Measurement of endometrial blood flow in guinea-pig uterus by clearance of intraluminally applied 133xenon: effects of oophorectomy, estrogen treatment and pregnancy

Endometrial blood flow (EBF) was studied atraumatically in guinea-pigs by the 133xenon clearance technique. With the aid of an otoscope, a xdnon-saline solution was deposited via the vagina through a cannula into the uterine lumen. Radioactivity curves were obtained by a small external scintillation detector. Oophorectomy lowered total flow wheras this was markedly increased (also per unit weight) by estrogen treatment, alone or in combination with oophorectomy. During early pregnancy there was a tendency to increase in the flow, while the values (for the parietal decidua) were markedly reduced at later stages of pregnancy. In the fetus-placenta unit (133xenon solution injected intra-amniotically) the flow was three times higher than in the parietal decidua at this advanced stage of pregnancy.