Intravitreal human chorionic gonadotropin decreases intraocular pressure in rabbits: mechanism of action

Intravitreal injection of purified human chorionic gonadotropin (hCG) in rabbits decreased intraocular pressure (IOP). A dose-dependent decrease in IOP was observed with intravitreal hCG concentrations at 30 nM and 100 nM. The onset of this effect was later than 10 hr following the injection and it lasted for more than 24 hrs. The purified beta-subunit of hCG caused a similar decrease in IOP with a short duration. The threshold intravitreal concentration was 10 nM. Unlike the intact hCG, the hCG beta-subunit was inactive as a gonadotropic agent to activate the adenylate cyclase in the rat testis. Intravitreal injection of rabbit luteinizing hormone, which was active as a gonadotropic agent, had no effect on IOP in 4 intravitreal concentrations ranging from 1 nM to 30 nM. These observations indicate that the mechanism of IOP decrease by intravitreal hCG is not related to its gonadotropic action. The IOP decrease in rabbits due to intravitreal hCG or its beta-subunit is probably related to a contaminant or an immune reaction.

Pharmacodynamics of the antiprogesterone RU486 in women after oral administration

The pharmacokinetic characteristics of RU486 and its acute effects on anterior pituitary hormone secretion after oral administration were examined in six normal women. Serum RU486 concentrations were determined by a radioimmunoassay. The absorption of RU486 was rapid with peak serum levels reached approximately 90 minutes after a single oral dose (4 mg/kg). The disappearance of RU486 and its metabolites conformed to a noncompartmental model with a mean apparent half-life of 53.7 +/- 6.9 hours. The mean apparent volume of distribution and clearance rate were 1.47 +/- 0.25 l/kg and 1.04 +/- 0.09 1/hour, respectively. In comparison with a control group of normal women (n = 9), there were significant elevations in transverse mean cortisol levels in the RU486 group (P less than 0.01). However, mean adrenocorticotropic hormone (ACTH) levels and the diurnal pattern of ACTH and cortisol secretion were not changed. RU486 induced a mild prolactin (PRL) elevation (P less than 0.01), whereas thyroid-stimulating hormone (TSH) and luteinizing hormone (LH) levels were not altered. In view of the relatively slow clearance rate for RU486 and its metabolites, our findings suggest that the pharmacologic action of RU486 is prolonged after a single oral dose.

Extra-pituitary action of luteinizing hormone releasing hormone on intraocular pressure

Luteinizing hormone releasing hormone (LHRH) given intraventricularly caused a delayed, significant decrease of intraocular pressure (IOP) in adult female rabbits for a prolonged period, but only elevated plasma gonadotropins for a few hrs. Intravenous injections of LHRH caused a similar elevation of plasma gonadotropins without any effect on IOP. It indicates that LHRH initiates a mechanism in the central nervous system to decrease IOP, which is unrelated to the conventional LHRH-gonadotropin axis.

Hypercortisolism in patients with functional hypothalamic-amenorrhea

Hypercortisolism was found in patients with functional hypothalamic amenorrhea (HA) in preliminary short term studies conducted during the morning hours (0800-1100 h). This observation prompted us to characterize the circadian and pulsatile patterns of serum cortisol and LH levels at 15-min intervals for 24 h in 10 women with functional HA and in 7 normal women during the early follicular phase of their cycles. The mean integrated 24-h serum cortisol levels (area under the curve) were significantly (P less than 0.01) higher in the HA patients than in normal women. The mean cortisol levels in the HA patients were elevated (P less than 0.005) compared to those in the normal women during the daytime hours (0800-1600 h), but not during the evening (1600-2400 h) and sleeping hours (2400-0800 h). This selective hypercortisolism during the waking period of the day was almost entirely related to increased duration and amplitude of secretory episodes (peak area) rather than a change in pulse frequency. The serum cortisol increments in response to a noon meal that occurred in normal women were markedly impaired (P less than 0.01) in the HA patients. Compared with that in the normal women, mean LH pulse frequency was reduced by 30% in the HA patients. The 24-h mean LH levels and mean LH pulse amplitude were not significantly different from those in the normal women. However, among the HA patients there were marked individual differences in LH pulse frequency and amplitude, with prolonged interpulse quiescent periods, indicative of dysfunction of the hypothalamic GnRH pulse generator. We conclude that neuroendocrine activation of the ACTH-adrenal axis and inhibition of the GnRH pulse generator in women are associated with HA. Further, spontaneous resumption of normal cyclicity occurred in the majority (8 of 10) of the HA patients with no medical treatment, suggesting that this syndrome is a reversible hypothalamic disorder of a functional nature.

Bone marrow cryopreservation and clinical implications in autologous bone marrow transplantation

A simple, rapid and effective technique using the IBM (Cobe)-2991 cell processor for the concentration of buffy coat cells from large volume marrow has been well adopted (n = 16). Only about one-eighth of the original volume was obtained while retaining more than 90% of the total nucleated cells to be cryopreserved in polyolefine bags with TC-199 culture medium and final 10% dimethylsulfoxide (DMSO) (n = 9), processed by a computerized Nicool ST-20 (France) programmed freezer and stored in a vapor phase of liquid nitrogen at -196 degrees C. Stem cell assay by CFU-GM after thawing yielded a mean of 50.39 +/- 19.54% which has been satisfactory for clinical implementation. So far, three cases with hematological malignancies had been rescued by autologous cryopreserved marrow after supralethal doses of chemoradiotherapy. Two patients with acute nonlymphocytic leukemia transplanted in 1st remission as of Oct. 31 had been disease free for 178+ and 157+ days, respectively, after transplant which was taken at the corresponding age of 53 and 42 years. The other patient who was a victim of Hodgkin's disease, stage IV, and was transplanted in 3rd remission, expired on the 59th day because of the complication of idiopathic interstitial pneumonitis despite excellent granulocytopoietic reconstitution. The preliminary results are encouraging for further exploitation, especially for those who would otherwise be candidates for allogeneic bone marrow transplantation but are limited by age or lack of an HLA-identical sibling to serve as marrow donors.

Gonadotropin and prolactin secretion increases during sleep during the puerperium in nonlactating women

To investigate the neuroendocrine changes that regulate initiation of normal menstrual function after parturition, serum LH, FSH, and PRL concentrations were determined at 20-min intervals for 12-24 h in eight nonlactating postpartum women on a weekly basis between postpartum days 10-26. Sleep was monitored by EEG. On postpartum day 10, serum LH concentrations were similar to early follicular phase levels in normal cycling women, while FSH concentrations were lower than early follicular phase levels. Mean LH pulse frequency during each postpartum interval was 3.6 +/- 0.6 (+/- SE), 4.4 +/- 0.6, and 4.1 +/- 0.8 pulses/12 h on postpartum days 10-11, 17-21, and 24-26, respectively. Because mean serum LH levels and LH pulse frequency did not change significantly between postpartum days 10 and 26, the results from the two or three studies in each woman were combined for the purpose of comparing LH pulse characteristics during the waking and sleeping periods. During the waking hours, mean LH pulse frequency (6.1 +/- 0.5 pulses/12 h) was significantly greater than during sleep (4.1 +/- 0.4 pulses/12 h; P less than 0.02). The amplitude of the serum immunoreactive LH pulses (P less than 0.05) and bioactive LH levels (P less than 0.05) were significantly higher during sleep than during the waking period, with five of the eight women having higher sleep-associated immunoreactive LH and bioactive LH levels between postpartum days 17-26. These changes were associated with an increase in the bioactive to immunoactive LH ratio from 3.3 +/- 0.4 (awake) to 4.5 +/- 0.5 (sleep; P less than 0.05). Although serum PRL levels remained elevated during the puerperium, the diurnal pattern of PRL secretion was conserved. With each successive week postpartum, serum PRL concentrations declined. These results suggest that the increment in LH secretion (and, by inference, increased GnRH secretion) during sleep is a feature of postpartum pituitary-ovarian reactivation. Although the mechanism(s) responsible for the increase in GnRH secretion is not known, this hormonal pattern is analogous to that during early puberty and during recovery from anorexia nervosa and hypothalamic amenorrhea. Taken together, these findings provide evidence to support the concept of a centralized preprogrammed scheme for pituitary-gonadal reactivation.

Pulsatile beta-endorphin release from the human pituitary in vitro

An in vitro perifusion system was used to characterize spontaneous immunoreactive beta-endorphin (i beta-END) release from 10 human fetal (20-23 weeks gestation) and 2 human adult anterior pituitaries. Spontaneous i beta-END release from fetal anterior pituitaries was pulsatile, with a mean (+/- SE) pulse interval of 9.1 +/- 0.5 minutes, pulse amplitude of 120.8 +/- 46.1 pg with nadir to peak increment of 106.0 +/- 32.9%, and overall release rate of 209.7 +/- 65.0 pg/2 minutes. Blockade of calcium activity with 10 microM verapamil and 4 mM EGTA suppressed the frequency and amplitude of the spontaneous pulsatile i beta-endorphin release (n = 2). Administration of 2 nM human CRF for 20 minutes at the end of 2 perfusions induced 205 and 883% increases of i beta-END release over the preceding basal levels. Administration of 2 nM CRF for 50 minutes at the end of another perifusion led to a greater and prolonged increase (maximum 4620% relative to the immediately preceding basal level) in i beta-END release. Addition of 56 mM KCl during the last 20 minutes of this prolonged CRF stimulation further increased i beta-END release (to 7680% relative to the baseline preceding the CRF stimulation). Each of 4 quarters of adult anterior pituitaries (2 quarters each from 1 male and 1 female) also released i beta-END in a pulsatile fashion, with a pulse interval of 11.8 +/- 2.0 minutes, pulse amplitude of 7.4 +/- 0.8 ng with nadir to peak increment of 51.4 +/- 15.3%, and overall release rate of 21.7 +/- 2.9 ng/2 minutes. These studies demonstrate that i beta-END release from the isolated human anterior pituitary in vitro is characterized by high-frequency pulses, independent of hypothalamic stimulation. This spontaneous calcium-dependent pulsatile i beta-END release apparently reflects the activity of an intrapituitary pulse-generating mechanism.

Conjunctival involvement of lymphomatoid granulomatosis

Lymphomatoid granulomatosis is an angiocentric and angiodestructive lympho-proliferative disorder involving multisystems but rarely conjunctiva. We present a 62-year-old Chinese female with lymphomatoid granulomatosis who had an ulcerative conjunctival nodule. Conjunctival biopsy revealed pathological findings important for diagnosis and indicating progression of disease severity. To our knowledge, this is the first report to demonstrate pathological findings characteristic of lymphomatoid granulomatosis with conjunctival involvement.

Disruption of follicular maturation and delay of ovulation after administration of the antiprogesterone RU486

To investigate the role of progesterone in the follicular phase, we examined the effects of RU486 in eight normal cycling women studied with daily and frequent blood sampling (every 10 min for 10 h) during three menstrual cycles (control-treatment-recovery). RU486 (3 mg/kg, orally) was administered for 3 consecutive days after ultrasound documentation of a dominant follicle. In six of the eight women, RU486 was given after emergence of the dominant follicle, while in two women, RU486 was initiated during the preovulatory period when estradiol levels had exceeded 917 pmol/L. In the six women given RU486 after emergence of the dominant follicle, RU486 significantly prolonged the follicular phase duration from 15.6 +/- 1.9 (+/- SD) to 28.6 +/- 9.3 days (P less than 0.01) and extended the treatment cycle length to 42.3 +/- 9.1 (+/- SD) days (P less than 0.01). During RU486 treatment, mean serum estradiol levels decreased from 385 +/- 43 to 228 +/- 28 pmol/L (P less than 0.01), while LH, FSH, ACTH, cortisol, and progesterone levels changed little. LH pulse frequency and amplitude on the last day of RU486 administration did not differ from control values. Collapse of the dominant follicle was evident on ultrasound after RU486 administration and was not accompanied by uterine bleeding. In the two women treated during the preovulatory period, the follicular phase was not prolonged, and RU486 failed to delay the onset of the LH surge. Our findings indicate that RU486 treatment during the follicular phase interrupts normal follicular development, resulting in a delay of ovulation and a reinitiation of follicular recruitment.

Pituitary responses to synthetic corticotropin-releasing hormone: absence of modulatory effects by estrogen and progestin

To determine if the activity of the adrenocorticotropic hormonal-adrenal axis is modulated in part by estrogens and progestins, we have compared pituitary and adrenal responses to corticotrophin-releasing hormone in normal women during the early follicular, late follicular, and midluteal phases of the menstrual cycle and in four women undergoing ovariectomy who received estradiol (E2) implants alone or in combination with oral medroxyprogesterone acetate administration. Basal adrenocorticotropic hormone and cortisol levels (9:00 AM) and responses to ovine CRH were unaffected by variations in E2 and progesterone during each phase of the menstrual cycle. In women undergoing ovariectomy who received E2 replacement therapy, basal concentrations of adrenocorticotropic hormone and cortisol (9:00 AM) and the responses to human corticotrophin-releasing hormone were not altered by administration of E2 alone or E2 with medroxyprogesterone acetate. Under these experimental conditions, our findings suggest that physiologic changes in E2 and progesterone levels during the menstrual cycle and replacement doses of estrogen and progestin commonly used clinically do not significantly influence basal adrenocorticotropic hormone and cortisol levels or responsiveness to corticotrophin-releasing hormone.

Pulsatile rhythms of adrenocorticotropin (ACTH) and cortisol in women with endogenous depression: evidence for increased ACTH pulse frequency

Plasma ACTH and serum cortisol levels were measured at 20-min intervals for 24 h in six young women with unipolar endogenous depression and in eight normal women during the early follicular phase of the menstrual cycle. The women with depression had a marked increase (P less than 0.005) in mean ACTH pulse frequency [14.5 +/- 0.6 (+/-SE) pulses/24 h] compared with normal women (9.9 +/- 0.7 pulses/24 h), while mean ACTH pulse amplitude and 24-h transverse mean ACTH levels were similar in the two groups. In contrast, 24-h transverse mean cortisol levels were higher (P less than 0.02) in the depressed women (242 +/- 28 nmol/L) than in the normal women (163 +/- 10 nmol/L). This hypercortisolemia in the depressed women was accompanied by markedly increased (P less than 0.001) episodic cortisol secretion (286 +/- 24 X 10(2) nmol/L X min) compared with that in normal women (155 +/- 17 X 10(2) nmol/L X min), and the secretory episodes were both longer in duration (P less than 0.05) and of higher amplitude (P less than 0.05) in the depressed women. The circadian variations in ACTH and cortisol were maintained in these depressed women, and the times of the circadian nadir, as determined by cosinor analysis, were similar to those in the normal women. However, the mean length of the evening quiescent period of cortisol secretion was far shorter (P less than 0.005) in the depressed women (27 +/- 8 vs. 202 +/- 40 min). Moreover, the postlunch rise in serum cortisol was significantly higher (P less than 0.02) in the depressed women (204 +/- 29 vs. 111 +/- 15 nmol/L). These results provide evidence that the hypercortisolism in depressed women is associated with an increase in ACTH pulse frequency, expanded cortisol secretory episodes, including a greater postlunch rise in cortisol, and a shortened evening quiescent period of cortisol secretion. Our findings provide evidence for centrally mediated activation of the ACTH-cortisol system in women with depression without a phase shift in circadian rhythm.

Effects of stimulation of the ocular sympathetic nerves on IOP and aqueous humor flow

Ocular sympathetic nerves were stimulated chronically in awake rabbits using electrodes unilaterally implanted on the cervical sympathetic trunk. IOP was measured by pneumatonometry and aqueous inflow was measured by fluorophotometry. In each animal, continuous trains of 1 msec pulses were delivered by means of a portable electrical stimulator. Experiments were spaced by 1 week recovery periods. Stimulation was varied over a range of amplitudes (5-15 V) and frequencies (3-12 Hz). Continuous sympathetic stimulation produced an immediate sharp decrease in IOP followed by a gradual rise to pre-stimulation values which were attained 60-90 min after onset. A rebound increase in IOP occurred when stimulation was terminated. The magnitude of the initial IOP drop, the delay in the return to pre-stimulation IOP, and the rebound rise in IOP subsequent to termination of electrical stimulation were proportional to the stimulation frequency. Maximal effects were observed at 12 Hz, and stimulation with 8-10 Hz for 180 min caused a sustained reduction in anterior chamber aqueous humor flow. Topical 2% phentolamine 1 hr before stimulation markedly reduced IOP and abolished the acute IOP changes observed in untreated stimulated animals. Topical 1% timolol did not affect either the initial IOP drop or the rebound; however, the IOP recovered during stimulation to values greater than pre-stimulation IOP. We conclude that in rabbits the beta-adrenergic effect of prolonged sympathetic nerve stimulation is to decrease aqueous flow. Chronic electrical stimulation in awake animals provides an experimental model for studying the role of the ocular sympathetic nerves.

Treatment for severe burns of the chest wall with special reference to the involved ribs

Deep burns of the chest wall may involve not only the skin but also the muscle and bone. If the ribs and sternum are severely damaged, it may not be easy to carry out adequate debridement of partially necrotic ribs and sternum. A procedure termed segmental chiselling debridement of bones is herein described. Four cases are presented in which patients with severely burned chests were successfully treated without complications by use of this procedure in this hospital.

A genetic study of Behçet's disease in Taiwan Chinese

The frequency of HLA-A, B and C antigen in 53 patients and HLA-DR, DQ and Dn antigen in 31 patients of Behçet's disease was studied. All patients were Chinese, and diagnosis was made according to the Japanese Research Committee on Behçet's disease. A significantly increased incidence of HLA-B51 (P less than 0.001) and a significantly decreased incidence of HLA-B16 (P less than 0.01) was found. No significant difference was found in HLA-DR, DQ and DN antigens.

Intrinsic pulsatility of ACTH release from the human pituitary in vitro

An in-vitro perifusion system was used to investigate spontaneous ACTH release from human fetal (21-23 weeks gestation) and adult pituitaries. The pattern of ACTH release from fetal pituitaries (n = 7) exhibited a remarkable pulsatile character with a mean (+/- SEM) pulse interval of 11.3 +/- 0.8 min. The mean pulse amplitude was 49.7 +/- 6.3 pg, with a nadir to peak increment of 90.7 +/- 10.4%. The mean ACTH release rate was 87.2 +/- 13.3 pg/2 min. Addition of the calcium chelator EGTA (4 nM) to the perifusion medium induced a significant (P less than 0.01) decrease in both ACTH release rate (from 102.0 +/- 8.5 to 52.0 +/- 9.9 pg/2 min) and ACTH pulse amplitude (from 57.7 +/- 2.8 to 31.3 +/- 4.6 pg) (n = 3). Administration of either 2 nM corticotrophin releasing factor (CRF) or 56 mM KCl induced 10- and 2-fold increases in ACTH secretion, respectively (n = 2). Quarters of adult human pituitaries (n = 6) also secreted ACTH in a pulsatile fashion, with a pulse interval of 14.8 +/- 1.7 min, pulse amplitude of 86.7 +/- 10.0 pg, nadir to peak increment of 84.5 +/- 9.8%, and overall release rate of 167.2 +/- 8.8 pg/2 min. These studies demonstrate that ACTH release from the isolated human pituitary in vitro is characterized by high frequency/low amplitude pulses, independent of hypothalamic stimulation. Accordingly, this spontaneous calcium-dependent pulsatile ACTH release apparently reflects the activity of an intrinsic intrapituitary pulse-generating mechanism.

Characterization of the twenty-four hour secretion patterns of adrenocorticotropin and cortisol in normal women and patients with Cushing's disease

The episodic and circadian secretory patterns of ACTH and cortisol were studied in five patients with Cushing's disease (CD) and nine normal women by repetitive (every 20 min) venous blood sampling. In contrast to normal women, the 24-h transverse mean plasma ACTH levels were more than 3-fold greater (P less than 0.01), and the 24-h transverse mean serum cortisol levels were more than 2-fold higher (P less than 0.001) in the CD patients. Using a pulse detection algorithm, we found that the elevated ACTH levels in CD were accounted for, in part, by the more than 2-fold greater elevation in mean pulsatile ACTH amplitude (P less than 0.01), while the mean frequency of episodic ACTH and cortisol secretion was similar to that in normal subjects (10-12 episodes/24 h). Although a relatively close temporal relationship between ACTH and cortisol secretory episodes was found (r = 0.70 and 0.72, normal and CD groups, respectively), the increased ACTH pulse amplitude was not consistently associated with comparable cortisol pulses in CD patients. Circadian rhythms were identified for ACTH in two CD patients and for cortisol in all CD patients. The timing of the acrophases and nadirs for cortisol was not significantly altered compared to that in the normal group. After the noon meal, the normal postprandial elevation in cortisol was depressed or absent in the CD group. ACTH and cortisol responses to CRH in four CD patients were highly variable, but were not significantly different from those in normal subjects. These studies demonstrate that the elevated plasma ACTH levels in CD are sustained in part by increased ACTH pulse amplitude without significant alterations in pulse frequency. Despite the persistently high ACTH levels, the circadian variation of cortisol is maintained. The finding of an abnormal postprandial cortisol response in CD may provide an additional biological marker for CD.

Intrinsic pulsatility of luteinizing hormone release from the human pituitary in vitro

An in vitro perifusion system was used to investigate the spontaneous luteinizing hormone (LH) release from 10 human fetal (21-23 weeks of gestation) and 1 adult female pituitaries. The pattern of LH release from fetal pituitaries (n = 6) exhibited a remarkable pulsatile character with a mean (+/- SE) pulse interval of 12.7 +/- 1.7 min. The mean pulse amplitude was 5.2 +/- 0.9 mIU with a nadir to peak increment of 69.5 +/- 6.4%. The mean LH release rate was 12.3 +/- 3.3 mIU/2 min. Blockade of calcium activity with 0.1 mM verapamil and 4 mM EGTA suppressed the frequency (from 1 pulse/12-20 min to 1 pulse/50-100 min) and amplitude (from 5.4-5.7 mIU to 1.4-2.1 mIU) of this spontaneous pulsatile LH release (n = 2). Administration of 8 nM gonadotropin-releasing hormone induced 255 and 954% increases in LH secretion (n = 2). Each quarter of an adult human pituitary also secreted LH in a pulsatile fashion, with a pulse interval of 15.2 +/- 5.6 min, a pulse amplitude of 5.4 +/- 0.6 mIU, a nadir to peak increment of 67.5 +/- 5.2%, and an overall release rate of 14.8 +/- 0.9 mIU/2 min. These studies demonstrate that LH release from the isolated human pituitary in vitro is characterized by high-frequency/low-amplitude pulses, independent of hypothalamic stimulation. Accordingly, this spontaneous calcium-mediated pulsatile LH release apparently reflects the activity of an intrinsic intrapituitary pulse-generating mechanism.

Neurosecretion of human hypothalamic immunoreactive beta-endorphin: in vitro regulation by dopamine

An in vitro perifusion system was used to investigate immunoreactive beta-endorphin (beta-END-I) release from adult human hypothalami in response to dopamine (DA) and the DA receptor antagonist haloperidol (HAL). Administration of a 1 microM pulse of DA consistently elicited a mean (+/- SE) 88 +/- 9% increase (p less than 0.05, n = 5) in beta-END-I release, whereas 1 microM HAL had no effect. Administration of 1 microM DA during three perifusions in which 1 microM HAL was added to the medium failed to alter basal beta-END-I release. In contrast, DA did evoke an acute 230 +/- 31% increase (p less than 0.05) in beta-END-I release during three matching perifusions with medium containing the alpha-adrenergic antagonist phentolamine. These studies demonstrate that DA can stimulate in vitro release of beta-END-I from the adult human hypothalamus by a DA receptor mediated mechanism.

Characteristics of menopausal women seeking assistance

Using a questionnaire approach, we have determined the demographic, social, and clinical characteristics of the first 100 participants attending our menopause clinic. Of the respondents, 79% reported onset of significant physical symptoms and 63% significant emotional symptoms during the menopause. Among the participants, 65% had varying degrees of depression as determined by the Zung self-rating depression scale. This seemed to be more prevalent in patients with previous pelvic operations. Only half the women were on a regimen of estrogen replacement therapy, and most were receiving estrogen in an unopposed fashion. In our menopause clinic, more than half the women were over their ideal body weight, which is in contrast to the popular misconception that only thin women develop menopausal symptoms. Data from our patients suggest the need for multidisciplinary menopause clinics to adequately address the physical and emotional problems of menopausal women.

Central nervous system and peripheral mechanisms in ocular hypotensive effect of cannabinoids

Systemic administration of cannabinoids decreases intraocular pressure (IOP). To determine whether the mechanism of action originates in the central nervous system, we administered various cannabinoids into the cerebral ventricles of conscious New Zealand albino rabbits. When delta 9-tetrahydrocannabinol (delta 9-THC), delta 8-tetrahydrocannabinol, cannabinol, and cannabidiol were given intravenously, only delta 9-THC produced dose-dependent ocular hypotension and miosis. Bolus administration into the cerebral ventricles or ventriculocisternal perfusion of delta 9-THC did not change IOP or pupil size. In urethane-anesthetized rabbits, IOP and blood pressure were lowered by intravenous administration of delta 9-THC but not by bolus cerebral administration. These observations indicate that the action of cannabinoids on IOP does not originate in the central nervous system. Alteration of blood pressure may be involved in the mechanism of ocular hypotension induced by delta 9-THC.

Purification and some properties of glycerol-3-phosphate dehydrogenase from rabbit skeletal muscle mitochondria

Glycerol-3-phosphate dehydrogenase (E. C. 1. 1. 99. 5) was solubilized from rabbit skeletal muscle mitochondria by Triton X-100 and purified through hydroxyapatite column chromatography, DEAE-Sepharose CL-6B column chromatography and sucrose density gradient ultracentrifugation. The preparation was electrophoretically pure, the total recovery was 10% and the specific activity had been increased 200-fold. The apparent molecular weight of the enzyme polypeptide was 69,000, it existed in the form of enzyme-Triton X-100 complex with a Stokes' radius of 59 A and a sedimentation coefficient of 10.7 S. There were 1.7 mg Triton X-100 and 26 micrograms phospholipid per mg protein of the preparation. The enzyme absorbed at 410 and 460 nm which could be attributed to non-haem iron and FAD respectively. Both of the absorption would be largely diminished by adding the substrate glycerol-3-phosphate.

Human fetal hypothalamic GnRH neurosecretion: dopaminergic regulation in vitro

An in-vitro perifusion system was used to investigate GnRH release from fetal (21-23 weeks gestation) human hypothalami in response to dopamine (DA) and the DA receptor antagonist haloperidol. Administration of 1 mumol/l DA during five perifusions in which 1 mumol/l haloperidol was added to the medium failed to alter basal GnRH release. In contrast DA evoked a rapid and sustained 95.8 +/- 20.3% increase (P less than 0.01) in GnRH release during five matching perifusions with medium containing the alpha-adrenergic antagonist phentolamine. While exposure to 0.01 mumol/l DA failed to alter basal GnRH release during three perifusions, 0.1 mumol/l DA elicited a 145.7 +/- 65.2% increase (P less than 0.05) in GnRH release in three matching perifusions, indicating a dose-dependent effect. These studies demonstrate that DA can stimulate in-vitro release of GnRH from the mid-gestation fetal human hypothalamus by a DA receptor mediated mechanism.

Increased cortisol production in women runners

Because we previously found increased basal serum cortisol levels in women runners, we examined adrenocortical function in amenorrheic running women (AR), eumenorrheic running women (R), and normal nonexercising women (NC) in further detail. Mean 24-h urinary cortisol levels were significantly elevated (P less than 0.001) in six AR [45.1 +/- 7.2 (+/- SEM) micrograms/24 h] and eight R (38.5 +/- 6.9 micrograms/24 h) compared to four NC (13.9 +/- 2.8 micrograms/24 h). After adrenal suppression with 2 mg dexamethasone, integrated responses and absolute maximal elevations in serum cortisol levels in response to 10 micrograms/m2 exogenous ACTH (1-24) administered as an iv bolus dose, were not significantly different among six AR, six R, and six NC. This dose of ACTH results in maximal steroid release. The disappearance rates of cortisol (5 mg, iv) after dexamethasone suppression were similar in four AR, five R, and four NC and corresponded to a two-compartment model with mean half-lives of 4.9 and 93.8 min, respectively. Cortisol-binding globulin levels were also similar among the groups. These data document higher cortisol secretion and suggest increased ACTH secretion in running women.

[Isolation and purification of bovine retina S-antigen]

Fresh bovine retinas were precipitated by ammonium sulfate, and further purified by the Sephadex G-200 column and the hydroxyapatite column. Through the SDS polyacrylamide gel electrophoresis and the isoelectric focusing gel electrophoresis, a single band of protein with molecular weight of 50,000 daltons, isoelectric point at 5.4-5.7, was identified as S-antigen. The yield of S-antigen from crude retina extract was 0.18%, higher than ever been reported. Guinea pigs were injected at the hind footpad with 5-30 micrograms of purified S-antigen which had been emulsified with an equal amount of complete Freund's adjuvant. There are severe uveitis findings in both clinical and pathological examinations. An experimental autoimmune uveitis animal model was successfully established. These results showed that it is an effective and rapid method for purification of retinal S-antigen.

Gonadotropin-releasing hormone neurosecretion in the human hypothalamus: in vitro regulation by dopamine

An in vitro perifusion system was used to investigate GnRH release from adult human hypothalami in response to dopamine (DA) and the DA receptor antagonist haloperidol (HAL). Administration of a 1-microM pulse of DA consistently elicited a mean +/- SE 218 +/- 59% increase (P less than 0.05; n = 5) in GnRH release, whereas 1 microM HAL had no effect. Administration of 1 microM DA during three perifusions in which 1 microM HAL was added to the medium failed to alter basal GnRH release. In contrast, DA did evoke an acute 98 +/- 39% increase (P less than 0.06) in GnRH release during three matching perifusions with medium containing the alpha-adrenergic antagonist phentolamine. These studies demonstrate that DA can stimulate in vitro release of GnRH from the adult human hypothalamus by a DA receptor-mediated mechanism.

Role of oxytocin in the modulation of ACTH release in women

To determine if oxytocin (OT) may have a modulatory role on corticotropin-releasing factor (CRF) and vasopressin (AVP) mediated ACTH-cortisol release in women, serial experiments were performed in which saline, OT, AVP and CRF were administered singly or in combinations. OT administration (2 IU intravenous bolus followed by 111 mIU/min infusion for 3 h) maintained a circulating concentration of 7.7 X 10(-8) M and did not significantly influence basal, AVP or CRF-induced ACTH-cortisol release. In contrast, OT inhibited significantly the potentiating effect of AVP on CRF-stimulated ACTH-cortisol release. These findings suggest that OT and AVP may modulate, in a reciprocal fashion, the CRF-mediated ACTH release and support the contention that OT may be involved in the neuroendocrine response to stress in women.

Corticotropin-releasing factor and intraocular pressure

The effect of centrally administered corticotropin-releasing factor (CRF) on intraocular pressure (IOP) was investigated using the technique of ventriculocisternal perfusion. Various amounts of ovine CRF (0.01, 0.033, 0.1 and 0.33 micrograms/min) were perfused in conscious, male New Zealand albino rabbits for 1 hour. At a dose level of 0.1 or 0.33 micrograms/min, CRF caused an acute IOP decrease of 2.5 mmHg, which lasted for 30 min. Perfusions with CRF at 0.033 micrograms/min or higher caused delayed ocular hypotension, which began 20 hours after the perfusion and lasted for 2 days. Bolus intravenous injection of 3.3 micrograms CRF did not cause any IOP changes. These findings demonstrate that CRF can cause a centrally mediated IOP response. Superior cervical ganglionectomy eliminated the acute, not the delayed, CRF effect on IOP, indicating the involvement of ocular sympathetic nerves in the acute IOP effect.

Evidence for a hypothalamic site of action of clomiphene citrate in women

To examine the site of action of clomiphene citrate (CC), LH and FSH pulsatile amplitude, frequency, and responsiveness to GnRH (10 micrograms, iv) were studied in 11 women during the early follicular phase of the menstrual cycle. Six women received CC (150 mg/day) on cycle days 2, 3, and 4, while 5 women received placebo tablets. Blood samples were drawn at 10-min intervals for 8 h before and after the treatment regimen on cycle days 2 and 5, respectively. All women treated with CC had multiple follicular development, as determined by ultrasound. Peripheral levels of estradiol did not change after CC treatment, while progesterone levels decreased slightly. Mean levels of LH increased from 7.5 +/- 0.9 (+/- SEM) to 10.7 +/- 1.4 mIU/ml (P less than 0.05), and FSH increased from 6.7 +/- 0.9 to 10.1 +/- 0.9 mIU/ml (P less than 0.01). After exposure to CC, the pulse frequency of LH during an 8-h period increased significantly (3.3 +/- 0.7 on day 2 vs. 6.8 +/- 0.8 on day 5; P less than 0.01), while the pulse frequency of FSH increased from 3.8 +/- 0.6 to 5 +/- 1.4, as determined by computer pulse analyses. The pulse amplitude of LH and FSH was not significantly altered. In the placebo-treated group, neither pulse amplitude nor pulse frequency changed significantly between cycle days 2 and 5. Pituitary sensitivity to exogenous GnRH did not change after CC treatment. Since the pulsatile frequency of LH is governed by hypothalamic influences, these findings provide compelling evidence for a hypothalamic site of action for CC, probably by inducing an increase in the frequency of GnRH secretion.

Study of central regulation of intraocular pressure using ventriculocisternal perfusion

The ability of hypoosmotic solution, prostaglandin E1 (PGE1) and clonidine to influence intraocular pressure (IOP) by a central mechanism was studied using the technique of ventriculocisternal perfusion in conscious rabbits. IOP remained unchanged during the perfusion of 150 mOsm artificial cerebrospinal fluid. IOP rapidly increased by 15 mmHg during the perfusion of PGE1 at the dose of 1 or 3 micrograms/min. However, when PGE1 was perfused intravenously at the dose of 1 microgram/min, a similar IOP response was observed. Furthermore, during the ventriculocisternal perfusion of PGE1 a significant systemic absorption occurred. These observations indicate that the ocular hypertension during the ventriculocisternal perfusion of PGE1 is primarily due to the peripheral action of systematically absorbed PGE1. IOP gradually decreased by 3 mmHg during the ventriculocisternal perfusion of clonidine at the dose of 0.1 or 0.33 micrograms/min. Intravenous perfusion of clonidine at the same doses did not change the IOP. These results indicate that clonidine can lower IOP by a centrally mediated mechanism. Ventriculocisternal perfusion of clonidine (0.1 micrograms/min) in rabbits with unilateral superior cervical ganglionectomy lowered IOP in both eyes, indicating that ocular adrenergic innervation does not participate in this centrally mediated IOP response. However, the cardiovascular parameters of anesthetized rabbits were altered by the ventriculocisternal perfusion of clonidine (0.1 micrograms/min), suggesting that a change in systemic hemodynamics is involved in the central IOP effect of clonidine.

Observations of Langerhans' cells in leprosy using monoclonal antibody OKT6

Changes in the Langerhans' cells (LC) in seven cases of leprosy were observed using the monoclonal antibody OKT6. In the epidermis of the lesions of most of the leprosy cases, the processes of LC were reduced or diminished. Some LC were disintegrated. In two BT cases in the upgrading (type 1) reactional stage, either increased numbers and aggregation of OKT6-positive cells in clusters or their disintegration was seen in different areas of the epidermis.

Effects of timolol on intraocular pressure following ocular adrenergic denervation

The effects of timolol on the elevation of intraocular pressure induced by orogastric water-loading were studied in conscious pigmented rabbits which had undergone unilateral, superior cervical ganglionectomy. Each rabbit was studied without timolol treatment and with unilateral 2% timolol treatment, either to the innervated eye or to the denervated eye, 90 min before water-loading. Timolol, applied to the innervated eye, significantly reduced the elevation of intraocular pressure in that eye, but not in the fellow eye. Timolol, applied to the denervated eye, did not affect the elevated intraocular pressure in either the denervated or the fellow eye. These results demonstrate that ocular adrenergic innervation participates in the mechanism of ocular hypotensive action of timolol in water-loaded pigmented rabbits.