Non-involvement of the accessory olfactory system in the LH response of anoestrous ewes to male odour

In anoestrous ewes, male chemosignals elicit rapid increases in luteinizing hormone (LH) secretion that can ultimately lead to ovulation. To assess the possible involvement of the accessory (vomeronasal) olfactory system in the mediation of those chemical cues, we destroyed this pathway by vomeronasal organ electrocauterization (Exp. I) and vomeronasal nerve section (Exp. II). Neither of these lesions inhibited the LH response of ewes to the odour of the male. These results suggest that the vomeronasal system is not necessary to mediate the neuroendocrine response of the ewe to the male odour. As both surgical methods spared the main olfactory system but destroyed the vomeronasal system, it is likely that the main olfactory system is involved in the LH response to chemical stimulation in sexually experienced ewes.

Secretion of corticotropin releasing factor (CRF) and vasopressin (AVP) into the hypophysial portal blood of conscious, unrestrained rams

The secretion of Corticotropin-Releasing Factor (CRF) and Arginine Vasopressin (AVP) into sheep hypothalamo-hypophysial portal blood was investigated in conscious, unrestrained castrated rams. One to two hours after the onset of the collection, peripheral ACTH and cortisol levels were within the basal range in all the animals and portal CRF and AVP concentrations were low ranging between 5 and 90 pg/ml. After acute hemorrhage, a sharp increase in portal CRF and AVP was observed, inducing a sustained elevation of peripheral ACTH and cortisol. These data show that measurements of CRF and AVP in the portal blood of conscious sheep provide a good methodology to study the regulation of basal and stress-induced ACTH secretion.

Are differences in FSH concentrations involved in the control of ovulation rate in Romanov and Ile-de-France ewes?

Despite differences in FSH concentrations ranging from 1.5 ng/ml (Romanov ewes) to 4 ng/ml (Ile-de-France ewes) between the follicular and luteal phases, follicular growth (numbers of follicles growing, growth rates, maximum size reached) was morphologically similar between the two stages of the cycle. Injection of 750 i.u. hCG at Day 6 or 16 of the cycle triggered ovulation of 4.1 +/- 0.7 and 4.0 +/- 1.3 follicles in Romanov and 2.2 +/- 0.5 and 1.7 +/- 0.5 follicles in Ile-de-France ewes, respectively, demonstrating that functional differentiation was similar between the two stages of the cycle. As gonadotrophin environment differs between these two stages of the cycle, this suggests that there is a wide flexibility in the amount of gonadotrophins required to trigger terminal follicular growth and that ovarian requirements for gonadotrophins might work through thresholds. When Romanov and Ile-de-France ewes were given similar amounts of exogenous gonadotrophins (1250 i.u. PMSG, 750 i.u. hCG) after hypophysectomy, ovulation rates were close to the usual values (Romanov, 5.5 +/- 3.9; Ile-de-France, 1.4 +/- 0.5), demonstrating that differences in gonadotrophin concentrations during the follicular phase do not play a major role in the high ovulation of the Romanov compared to the Ile-de-France ewes.

Effect of time after castration on secretion of LHRH and LH in the ram

Hypophysial portal blood and peripheral blood were obtained from conscious, unrestrained rams to measure simultaneously the secretion of LHRH and LH in entire rams and rams which had been castrated for 2-15 days (short-term castration) and for 1-6 months (long-term castration). The apparatus for portal blood collection was surgically implanted using a transnasal trans-sphenoidal approach and, 4-5 days later, portal blood and peripheral blood were collected simultaneously at 10-min intervals for 8-9 h from 15 sheep. LHRH was clearly secreted in pulses in all three physiological conditions, but there were marked differences in pulse frequencies, which averaged 1 pulse/2-4 h in entire rams, 1 pulse/70 min in short-term castrated rams and 1 pulse/36 min in long-term castrated rams. In entire and short-term castrated animals, LH profiles were also clearly pulsatile and each LHRH pulse in hypophysial portal blood was associated with an LH pulse in the peripheral blood. In long-term castrated animals, LH pulses were not as well defined, because of the high basal levels and small pulse amplitudes, and the temporal relationship between LHRH and LH pulses was not always clear. These results demonstrate the pulsatile nature of LHRH secretion under the three physiological conditions and suggest that the irregular LH profiles characteristic of long-term castrates are due to an inability of the pituitary gland to transduce accurately the hypothalamic signal. The very high frequency of the LHRH pulses may be one of the major reasons for this, and is probably also responsible for the high rate of LH secretion in the long-term castrated animal.

A continuous flow intermittent mandatory ventilation with continuous positive airway pressure circuit with high-compliance reservoir bag

Unstable inspiratory pressure may reduce the benefits of intermittent mandatory ventilation and impose a greater work of breathing than some patients can tolerate. The authors evaluated a continuous flow intermittent mandatory ventilation with continuous positive airway pressure apparatus provided with a 10-L high compliance reservoir bag, separated from the ventilator circuit by a one-way valve. A pulmonary simulator was tested to generate a wide range of inspiratory peak flow rates. Pressures and flow rates were examined in different sections of the system, using PEEP levels up to 15 mm Hg and different fresh gas flow rates. The circuit offers many advantages, particularly considering the low inspiratory pressure drop and the low fresh gas flow rates needed for optimal function.

Effect of adrenalectomy on LH release in sheep during the anoestrous season

An experiment was conducted to measure LH pulse frequencies in bilaterally adrenalectomized Ile-de-France ewes during the mid-anoestrous season. Seven ewes were adrenalectomized under general anaesthesia and maintained on daily injections of 3 mg deoxycorticosterone acetate (DOCA). Adrenalectomy did not affect the patterns of LH release and the mean intervals between pulses in the adrenalectomized and sham-operated control ewes were 48 and 52 min respectively. Small implants of oestradiol significantly reduced the frequency of LH pulses in both groups and, in the presence of oestradiol, there were no differences in LH release between adrenalectomized and sham-operated ewes, with the mean interpulse intervals being 91 and 89 min respectively. In a second experiment, designed to assess the effects of DOCA on LH release, the mean interpulse intervals in unoperated control ewes (46 min) and unoperated ewes given daily injections of 3 mg DOCA (47 min) were similar to those observed in adrenalectomized and sham-operated ewes. In the presence of small implants of oestradiol, the combination of DOCA and oestradiol decreased the pulse frequency significantly more than oestradiol alone (mean interpulse intervals of 85 and 65 min respectively) suggesting that DOCA may act as a progestagen in sheep. Thus alternative treatments to DOCA for the maintenance of adrenalectomized sheep must be found for future studies on the role of adrenal steroids in the reproductive system. It appears that adrenal steroids do not play a major role in the seasonal changes in LH release in the ewe.

Effects of experimental cryptorchidism and subsequent orchidopexy on seminiferous tubule functions in the lamb

The reversibility of damage caused by cryptorchidism to the seminiferous tubules of the lamb was investigated at various ages. Lambs were made bilaterally cryptorchid either at birth or at 2 months of age. Then orchidopexy was performed at either 2 or 4 months of age. In permanently cryptorchid lambs, spermatogenesis stopped completely, and Sertoli cell function, as measured by FSH receptors, androgen receptors and ABP, was much reduced (-96%, -86% and -81%, respectively). Orchidopexy allowed the cryptorchid seminiferous epithelium to grow again, but the more differentiated the germ cells, the less they were capable of restoration. Even in 0- to 2- and 0- to 4-month-old temporarily cryptorchid lambs that had recovered normal Sertoli cell function, 16 to 49% of the tubules still were empty. It was concluded that cryptorchidism irreversibly damages the seminiferous tubules at a level other than the hormone receptors.

[Pseudoaldosteronism caused by licorice. Review of the literature and description of 4 clinical cases]

Metabolic and toxic effects caused by prolonged daily ingestion of Liquorice are well known in the literature. Such acquisition doesn't seem to be known enough by practitioners and by common people. Besides active substances such as Glycyrrhizin , Liquorice contains even steroids similar to the adrenocortical ones; among these the most important is Beta-Glycyrrhetinic acid. This one, in vivo and in vitro, produces salt and water retention by means of a "DOCA-like" mineral-corticoid mechanism, and clear suppression of the Renin-Angiotensin-Aldosterone axis. A low plasmatic level of Renin and Aldosterone is a common feature. The clinical picture in many ways is similar to the primary Aldosteronism and for this reason the above mentioned syndrome is usually called "Pseudoaldosteronism". Symptoms and signs can be classified into the following main groups: symptoms linked with water and salt retention: oedemas, hypertension, cardiac involvement. Symptoms linked with serum Potassium depletion: asthenia, paralysis (due to Potassium deficiency), myopathy with myoglobinuria. The diagnosis is essential based on an accurate pharmacological dietetic history, aimed to recognise an excessive use of Liquorice (pure or more often as substitute) in the screening of hypertension with or without hypopotassemia. Finally, the more or less quick normalisation of blood pressure and biochemical signs--as an "ex juvantibus" criterion--is the most important reason for the diagnosis. After a wide survey of the literature, the clinical and biological picture in four patients with chronic Liquorice ingestion and Pseudoaldosteronism syndrome is described.

[Insulin therapy with microinfusion devices. Review of the literature]

The aim of the present work is to review the most recent data in the literature about the problems, true advantages and limits of continuous infusion of insulin in the therapy of insulin-dependent diabetes mellitus. After a report on the kinds of microinfusors available today and the possible ways of continuously administering insulin, some aspects of CSII (continuous subcutaneous insulin infusion) are reviewed: indications, side effects, patterns of insulin flow programming and psychological aspects. The need for preliminary selection of the patients who are to undergo instructive courses is emphasized. Then the data from the literature about the effects of continuous infusional therapy in relation to metabolic alterations and the later complications of diabetes are analysed. These important aspects are compared with the results of conventional insulin therapy. Finally, the effects of continuous infusional therapy during pregnancy, on brittle diabetes, on insulin sensitivity and on the "down phenomenon" are analysed. It is concluded that, even if you cannot formulate a definitive opinion about this topic, microinfusors can be a functional means of achieving excellent metabolic control. Nevertheless, their greater efficiency in comparison with the so-called optimized insulin therapy has not been unequivocably demonstrated, and the real need for them at the present time appears to be exceptional.

Production, freezing and transfer of embryos from a bluetongue-infected goat herd without bluetongue transmission

In order to import non-seasonal Creole goats from the Carribean to Europe for an experimental purpose, thirty Creole goats were treated with 10 mg of FSH; embryos were collected at slaughter, washed and deep frozen. After rapid thawing, they were reimplanted surgically into European dairy goats. Twenty-four females ovulated but only 17 of the ovulating females had functional corpora lutea (CL) at collection. Ovulation rate (CL goat ) and recovery rate (embryo CL ) were 13.8 and 78% for females with functional CL. Of 191 embryonic structures collected, 79% were considered suitable for deep freezing: 23% were young blastocysts, 47% were expanded blastocysts, and 30% were zona-pellucida (zp)-free and zp-damaged embryos. Seventy-eight embryos were thawed and 63 were reimplanted. Sixty-eight percent of the recipient females delivered 19 kids. The percentage of kids born relative to good-quality re-implanted embryos was higher for zp-free embryos (64%) than for young and expanded blastocyts (36%). Forty-seven percent of the donor females had strong positive serological reactions for bluetongue virus antibodies against serotypes 6 and 14. However, no recipient goats or newborn kids were positive. Virus isolation attempts on the collection media and last embryo washes were negative.

Influence of transport stress on trichostrongylid infection in feedlot beef cattle

The influence of stresses due to transport of beef cattle and their allotment to feedlots on trichostrongylid infection was studied. The greatest increases in worm egg counts and serum pepsinogen levels were seen at 5 h and 30 days after allotment. These apparently resulted from reactivation of arrested larvae which the animals ingested while grazing during late autumn at the breeding farm.

Non-pheromonal stimulation by the male of LH release in the anoestrous ewe

In the anoestrous ewes, the introduction of rams leads to an increase in the secretion of LH and ovulation. Several studies have led to the hypothesis that a ewe's response to the male is mediated by pheromones, implicating a prevalent role of olfaction. In order to analyse if sensory cues other than smell could influence the ewe's physiological response to the male, an olfactory bulbectomy which destroys both main and accessory systems was performed in seven Ile-de-France ewes with a surgical laser. When presented to intact males, the ewes still reacted to the rams by displaying a LH release similar to the controls (n = 11) whereas no response was obtained after ram's fleece stimulation. This suggests that other sensory cues may replace the pheromone to trigger LH release.

[Autonomic neuropathy in reduced glucose tolerance]

33 subjects belonging to I.G.T. class according to N.D.D.G. criteria and controlled in our ambulatory, have been studied for the response to the tests usually employed for the investigation of parasympathetic and sympathetic cardiovascular innervation. We have found pathological values for the SL1 test and borderline values for SL2 and LS tests; on the contrary all the other tests presented normal values. The Authors conclude that signs of deterioration of cardiac and vascular innervation, especially regarding the parasympathetic nervous system, can be present also in the subjects showing a small glucose metabolism alteration. This subclinical alterations do not depend on factors which can interfere with the responses to the tests (as age, boyd weight, sex and presence or absence of diabetic familiarity) but on glucose metabolism alteration. Hence also the subjects with I.G.T. have to be considered as a at risk population, like the neuropathic diabetics.

Functional evaluation of a CPAP circuit with a high compliance reservoir bag

Continuous positive airway pressure is widely used in the treatment of ARF and an evaluation of the systems is important. The authors used an artificial model to test a continuous flow system with a high compliance reservoir bag. The results confirm that the system is effective in maintaining positive pressure stability within a wide range of inspiratory peak flow rates, even when a low fresh gas flow rate is employed. Nevertheless, rebreathing of expired gases is possible and may be noticeable at high expiratory flow rates, caused by the high compliance of the reservoir bag.

Effects of fetal hypophysectomy and the in vitro treatment by pituitary extracts on the maturation of cultured ovine fetal adrenal cells

In the first series of experiments, the ability of cultured adrenal cells from 113-day-old ovine fetuses to produce both cAMP and corticosteroids in response to ACTH-(1-24) or to fetal (FPE) or newborn acidic pituitary extracts (NPE) was investigated daily. Basal cAMP output did not change during the culture period. When cells from 124-day-old ovine fetuses, or from 5-day-old lambs, were repeatedly stimulated (2 h/day for 4 days) by ACTH-(1-24) or by pituitary extracts, the cAMP responses increased with the same pattern. Outputs on day 4 were 7-fold higher than those on day 1 for ACTH-(1-24)-matured cells or for cells matured by FPE or NPE. The steroid output induced by ACTH-(1-24) or by FPE or NPE developed identically during the experiment to become, on day 4, more than 40-fold higher than on day 1. The response to ACTH-(1-24) on day 5 was also identical both in cAMP and corticosteroids whether the cells had been previously treated with ACTH-(1-24) or with FPE or NPE, In the second set of experiments, adrenal cells from 124-day-old-ovine fetuses either intact of hypophysectomized (Hx) at 118 days of gestation were cultured for 6 days in the absence or presence of ACTH-(1-24). ACTH-(1-24) treatment resulted in a development of cAMP and corticosteroid responses to the hormone which was slower for cells from Hx than cells from control fetuses during the first 3 days of culture. Likewise both cAMP and corticosteroids responses to ACTH-(1-24) of adrenal cells from Hx fetuses cultured for 1 to 3 days in the absence of ACTH were lower than those of cells from control fetuses cultured under the same conditions. These results demonstrate that the pituitary from 124-day-old ovine fetuses contains trophic (and steroidogenic) substances in a sufficient amount to allow in vitro adrenal maturation. Moreover, it appears that high mol wt forms of ACTH, which are most probably extracted by the method we used, did not prevent the in vitro development of the response to ACTH-(1-24). Finally, they show that removal of pituitary hormones in vivo resulted in a decreased potency of fetal adrenal cells to respond in vitro to ACTH-(1-24).

Biochemical modifications involved in the maturation of the ovine fetal adrenal gland in late gestation: their modalities and regulation

During the last month of intra-uterine life, the steroidogenic response of the ovine fetal adrenal glands to ACTH increases and becomes maximal at the time of birth. This development involves modifications at different steps of the adrenocorticotropic hormone (ACTH) action mechanism. It has been shown that the enhanced capacity of the cells to produce cAMP is related to at least three factors: an increased number of ACTH receptors, increased activity of the Ns subunit of adenylate cyclase, and enhancement of guanosine 5'-triphosphate (GTP) availability. The ability to produce pregnenolone and the activity of both 3 beta-hydroxy steroid dehydrogenase/isomerase and 17 alpha-hydroxylase are mainly enhanced in the steroidogenic pathway. The infusion of ACTH for 5 days into 115 to 120-day old fetuses results in the development of most of these biochemical process. Similarly, ACTH can induce maturation of cultured fetal adrenal cells and some other proopiomelamocortin (POMC)-derived peptides can potentiate its acute steroidogenic activity in vitro. However, even in the absence of ACTH, the adenylate cyclase system and the steroidogenic potency of cultured cells increase but to a lesser extent than when ACTH is present in the culture medium. It is suggested that ACTH is the main trophic hormone of the ovine fetal adrenal during the last month of gestation, even if other stimulatory factors may also be important. The in vivo maturation of ovine fetal adrenal is blocked by the presence of some unknown inhibitory factors in the fetal circulation which are of likely extrapituitary origin.

The regulation of insulin and glucagon secretion by opiates: a study with naloxone in healthy humans

The presence of beta-endorphin and enkephalin in pancreatic islets suggests that opioid peptides may play a role in the regulation of pancreatic endocrine function. Since data in the literature are rather controversial, we examined the effects of different doses of naloxone on insulin and glucagon secretion in 21 healthy nonobese volunteers (6 women and 15 men) by measuring the variations of insulin and glucagon plasma levels following a 5-g i.v. glucose load before and during a 30-min naloxone infusion. Total amounts of 0.4 and 0.8 mg of naloxone failed to modify serum insulin and plasma glucose responses to glucose challenge. On the contrary, 0.2 mg/kg (i.e. 12-14 mg per subject as total amount) given to 3 women and 6 men led to a glucose-induced insulin release significantly lower than that recorded in basal conditions, with corresponding greater plasma glucose elevation. The suppressive effect of glucose on glucagon concentration was less pronounced during naloxone. Data reported here suggests that inhibition of opiate receptors in human pancreas occurs only with large amounts of naloxone. Moreover, they may indirectly support the stimulatory role of opioid peptides on insulin secretion in man, according to some experimental in vitro and in vivo studies. In addition, naloxone seems to reduce pancreatic A-cell sensitivity to hyperglycemia.

Fasciola hepatica: increase of glycogen phosphorylase activity due to prostaglandins

Both prostaglandin E1 (PGE1) and prostaglandin F2 alpha (PGF2 alpha) stimulate the glycogen phosphorylase (EC 2.4.1.1.) activity of Fasciola hepatica. Whole or sliced parasites were incubated with PGE1 (2.8 X 10(-7) and 2.8 X 10(-5) M) and PGF2 alpha (2.1 X 10(-7) and 2.1 X 10(-5) M) and enzyme activity was measured in homogenates prepared immediately following the incubation. No substantially different effect was noted between the two assayed doses of prostaglandins. Prostaglandins appeared to be less effective in sliced parasites.

A study of ovarian activity in the ewe using chronic catheterization of the utero-ovarian vein

Eighty-six adult, cyclic, anestrous and postpartum Ile-de-France ewes were placed under general anaesthesia. A catheter was inserted in the utero-ovarian vein (u.o.v.) of one or both ovaries in each ewe. The animals were kept unrestrained in pens and allowed to experience normal maternal behaviour, including suckling. Oestrus was detected with rams. Out of 167 catheters inserted, 70.7% allowed repetitive blood collection, 24.0% were obstructed for short periods and 5.4% remained completly blocked. Oestradiol- 17beta was assayed without extraction from the u.o.v. plasma samples. From these results, we conclude that this technique is suitable for investigating the mechanisms involved in the recovery of cyclical ovarian activity after parturition, particularly because the follicular response to endogenous gonadotropins can be assessed. This is not possible when plasma samples are obtained from a jugular vein.

Influence of the duration of daylight on prolactin secretion in the pig: hourly rhythm in ovariectomized females, monthly variation in domestic (male and female) and wild strains during the year

In wild boars and sows, plasma prolactin varied among seasons with highest levels in July and lowest during the winter months. In domesticated breeds of pigs, plasma prolactin of intact boars did not vary among seasons but plasma prolactin of gilts tended to be higher in the summer than in winter. However, this difference was more conclusive in ovariectomized as compared to intact gilts. There was not a significant circadian rhythm in hourly samples from ovariectomized gilts.

Adrenal maturation of the sheep fetus during late pregnancy

The mechanism by which adrenal growth is achieved and steroidogenesis is stimulated in the fetal lamb during late pregnancy has been studied. Fetal plasma ACTH levels remained roughly constant between 14 and 3 days pre partum (298 +/- 38 pg/ml), then increased to a mean of 634 +/- 89 pg/ml. The rise in ACTH did not occur before the pre partum rise in cortisol. The increase in adrenal weight was achieved in three periods, one of DNA duplication between two phases of cellular hypertrophy. Cellular hypertrophy was accompanied by an important biosynthesis of membrane proteins. This development might partly explain the increased production rate of cortisol by the fetal adrenals during late pregnancy. At the same time, the number of ACTH receptors per 2 adrenals increased 5-fold. There was a close correlation between the levels of fetal plasma corticosteroids and the number of ACTH receptors during late pregnancy. It has been suggested that receptor modulation is one of the factors responsible for the enhanced sensitivity of the fetal adrenals to ACTH just before parturition. Preliminary results on the endocrine regulation of that development are also presented.

Characterization of a cytoplasmic androgen receptor in the ram testis

An androgen receptor has been characterized in the cytosol fraction of testes from hypophysectomized adult rams after in vitro labelling with [3H]testosterone. It can be distinguished from the testicular androgen-binding protein (ABP) and from the plasma 5 alpha-dihydrotestosterone-binding protein by electrophoresis on 3.25% acrylamide gels (Rx = 0.5) and on agar gels (anodic migration). It sediments in the 4S region in sucrose gradient containing 0.4 M KCl. Its complex with testosterone dissociates very slowly (t 1/2 = 29 h at 0 degrees C), and is destroyed by heating at 50 degrees C for 30 min and by pronase. Its relative affinities for steroids are 5 alpha-DHT greater than T greater than 5 alpha-androstanediols greater than cyproterone acetate greater than estradiol greater than progesterone. The number of binding sites is limited (about 20 fmoles/mg protein) and the apparent equilibrium dissociation constant (KD) is 5 x 10(-9) M.

Influence of age and cortisone treatment on two intestinal lysosomal hydrolases in young rats

The effects of cortisone acetate injected i.p. on acid phosphatase and beta-glucuronidase in the small intestine mucosa of two groups of rats aging 12-14 and 20-22 days are reported. The following results are obtained: a) Total and free activities of the two enzymes show age-dependent differences. b) Cortisone acetate causes a very marked decrease of the enzymic activities only in the younger rats while being ineffective on the older ones. c) The kinetics of the enzyme release at 37 degrees C appear independent either of age or of cortisone injection. d) The "in vitro" lysosome labilizing treatments are ineffective.

[Spermatogenesis after testosterone supplementation in the hypophysectomized ram]

Six adult rams were hypophysectomized and immediately injected with 0,5 g (group A) or 2 g (group B) of testosterone per day for 2 weeks. Three normal rams (group C) received the solvent only. The testosterone concentrations in the testis (ng/g) were the same in groups A (23 +/- 7) and C (22 +/- 4) and 3 times higher in group B (72 +/- 18). There was an uptake of testosterone by the testis of the two supplemented groups. In the Rete Testis Fluid, the testosterone concentration was normal with 0,5 g/day (29 +/- 0.6 ng/ml). The testicular weight was maintained by the two treatments. However, spermatogenesis was abnormal in both supplemented groups; meiosis and spermiogenesis occurred normally, but the efficiency of spermatogonial divisions, as shown by the number of leptotene and zygotene primary spermatocytes, was greatly reduced (85%). The results indicate that testosterone alone in the Ram is unable to support complete spermatogenesis, which is contrary to that found in the Rat.

[The first manifestations of freemartinism in the calf fetus do not depend on XX/XY chromosomal chimerism]

In order to investigate the eventual role of XX/XY chimerism in freemartinism the vascular anastomoses between twin fetuses were surgically suppressed in litters with several fetuses, before the appearance of the first sexual anomalies. In three female fetuses isolated from their co-twins on days 37 and 45, the initial freemartin effect of gonadal and Müllerian inhibition was absent, in spite of an important XX/XY chimerism in the liver.

Cyclic AMP phosphodiesterase activity in Fasciola hepatica (L.) homogenates

The authors have studied the bahaviour of cyclic 3',5'-AMP phosphodiesterase in the 2,000 g supernatant of the Fascilola hepatica homogenate, under basal conditions and after addition of various substances. Dopamine remarkably inhibits the enzyme activity, imidazole causes a strong activation, while serotonin, theophylline, PGE1 and PGF2alpha appear to be ineffective.

High dose frusemide in established acute renal failure

The results of treatment with frusemide in 105 patients with established acute renal failure admitted during the past six years were reviewed and compared with control groups. Daily doses of 2,000 mg of frusemide administered from the day of admission onwards produced a significant increase in the number of patients who attained a diuresis and decreased the duration of oliguria.The reduction in the time spent in hospital and in the number of dialyses required suggests that the use of frusemide in these large doses is indicated in patients with severe established acute renal failure.