Angiotensin II--derived peptides devoid of phenylalanine in position 8 have full psychotropic activity of the parent hormone.

In this work we compared in rats the influence of heptapeptide 1-7-angiotensin II, hexapeptide 2-7-angiotensin II, pentapeptide 3-7-angiotensin II and angiotensin II on motility, stereotypy, learning of conditioned avoidance responses and recall of passive avoidance behaviour allowing to avoid aversive stimulation. The 4 peptides administered 15 min before the experiment, tended to increase the number of crossings, rearings and bar approaches in open field, significantly accelerated acquisition of conditioned avoidance responses and improved recall of the passive avoidance. All the peptides applied immediately before the experiment intensified stereotypy evoked by apomorphine in the dose 1 mg/kg and amphetamine in the dose 6.5 mg/kg given intraperitoneally. These results show full psychotropic activity of the examined fragments of angiotensin II, comparable with the activity of the parent octapeptide. Our previous hypothesis that the Val-Tyr-Ile-His-Pro fragment of angiotensin II is responsible for the psychotropic activity evoked by angiotensins in rats is thus confirmed.     

Effect of vitamin D3 administration on serum 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3 and osteocalcin in vitamin D-deficient elderly people

In elderly institutionalized people, confined to bedroom and receiving no vitamin D supplementation, the frequency of vitamin D deficiency is found very high. Systematic administration of vitamin D has, therefore, been proposed to correct vitamin D deficiency. Within this context, we studied 40 elderly institutionalized subjects (mean age 80.5 + 7.2 yr) with low 25(OH)D3 concentrations (4.4 + 1.8 micrograms/l). Sixteen of them (Group I) had low serum calcium concentrations (less than 2.3 mmol/l) and 24 (Group II) had normal serum calcium concentrations (from 2.3 to 2.6 mmol/l). As hypocalcemia has been shown to regulate 1,25(OH)D3 production independent of PTH in animals and in humans, we compared their respective responses to the administration of vitamin D3. Subjects received a total dose of 15 mg (600,000 IU) of vitamin D3 divided into 3 i.m. injections at one month intervals and were explored before therapy and one and 6 months after the last dose of vitamin D3. The treatment induced a similar marked rise in 25(OH)D3 levels (from 4.1 + 1.7 to 24.4 + 8.7 micrograms/l for group I and from 5.1 + 1.8 to 27.2 + 8.0 micrograms/l for group II) in both groups but increased the 1,25(OH)2D3 concentrations only in group I (from 22.9 + 6.9 to 32.6 + 11.3 ng/l). Meanwhile serum calcium concentrations rose in group I (to low normal range i.e. 2.31 + 0.07 mmol/l) and were unaffected in group II. These results suggest that hypocalcemia is a potent stimulator of renal 1-hydroxylase in elderly people. Furthermore, a transient significant (P less than 0.01) increase in serum osteocalcin (from 10.6 + 4.1 to 14.1 + 5.9 micrograms/l) could be observed in group I which demonstrates for the first time that the osteocalcin response of osteoblasts to stimulation by 1,25(OH)2D3 is retained in very old people.     

Comparative studies of Ca2+-dependent proteases (CDP I and CDP II) from Allomyces arbuscula.

Allomyces arbuscula, an aquatic fungus, contains two Ca2+-dependent neutral cysteine proteases (CDP I and CDP II), eluting respectively, at 0.07 and 0.2 M NaCl from DEAE cellulose columns. The purified CDP I has a Mr of 39 kDa whereas CDP II appears as a doublet of 43 and 40 kDa. Both enzymes require free thiol, the same concentration of Ca2+ for half maximal activation, and are inactivated by thiol protease inhibitors. Our results show that despite these similarities the two enzymes are different because affinity-purified CDP II antibodies do not cross-react with CDP I antigen in Western blots. In contrast, there is a strong cross-reaction between the two 43 and 40 kDa CDP II peptides and their respective antibodies. Both enzymes cleave preferentially the carboxy terminus of Arg and to a limited extent Lys on the cleavage site. This primary specificity is governed by the nature of the amino acids in the P2 and P3 positions. In general either Pro or Gly in P2 is required, with preference for Pro and in P3 position, Gly over Val. CDP II has higher catalytic activity than CDP I. The sulfhydryl reagent NEM is a more potent inhibitor of CDP I than CDP II. Although the function of the phosphorylable site(s) is not clear, both CDP I and CDP II contain phosphorylable serine residue(s).     

Effects of topically-applied olive oil on the response of hamster skin to single or multiple doses of 230kV X-rays.

The effects of topically-applied olive oil on the response of hamster skin to single or multiple doses of X-rays has been studied. The olive oil was applied either 15 min or 1 hour before the radiation exposures. The treatment did not alter the temporal pattern of development and recovery from the radiation injury. For single exposers, olive oil did not alter the 1- to 30-day average skin response. However, when it was administered at each treatment when three radiation fractions were given over a 4-day interval (3 fractions/4 days), a significant increase in the amount of dose recovered was found compared with control irradiated animals. For controls, the average amount of dose recovered per fractionation interval, (Dn-D1)/(n-1), was about 505 rad. For animals treated with olive oil 15 min before irradiation, it was about 720 rad; and for those treated 1 hour before irradiation, it was 782 rad. The data indicate a definite radioprotective effect of topical administration of olive oil, but at present the mechanism is not known.     

Central action of melanostatin (MIF-1) in mice

The effects of MIF-1 administered into a lateral ventricle of the brain were studied on the behaviour of mice in the open field test and hole test, apomorphine-induced stereotypy, morphine-induced catalepsy, and reactivity on thermal painful stimuli in the hot plate test. The last test was compared with a similar test with morphine administration. It was demonstrated that MIF-1 exerted a depressing effect on the behaviour of mice, increased the intensity of apomorphine-induced stereotypy and weakened chlorpromazine-induced catalepsy. Moreover, an analgesic action of MIF-1 was demonstrated which was blocked with naloxone. The results of these investigations indicated a significant central action of MIF-1 in mice and a participation of dopaminergic receptors in certain effects of MIF-1 on the behaviour of experimental animals.     

Effects of organic calcium antagonists and magnesium on the development of corazol kindling

In experiments on rats it was shown that i.p. administration of finoptin (verapamil), magnesium sulfate or ryodipine (an 1,4-dihydropyridine) 15 min before each daily injection of pentylenetetrazole (PTZ) in a subconvulsive dose (30 mg/kg i.p.) significantly (for 10-12 days delayed the development of pentylenetetrazole-induced kindling and attenuated kindled seizure reaction as compared with the controls. In animals sensitive to PTZ which were selected on the test of their reaction to previous single PTZ injection in a dose of 40 mg/kg finoptin, magnesium or finoptin + magnesium resulted in suppression of kindling development at late stages (after 2-week administration of drugs together with PTZ). After the withdrawal of the drugs there was a tendency to an increase of seizure reaction to the testing PTZ dose (30 mg/kg). The enhanced seizure susceptibility to test PTZ dose has being persisted during all observation period (8 months). Finoptin administered 15 min prior to PTZ had no effect on the severity of seizure reaction of fully kindled animals which had not received the drugs. The results obtained show that organic Ca-antagonists and magnesium delay the development of kindling induced seizure susceptibility, but cannot completely prevent it. The results also suggest that mechanisms of the chronic epileptogenesis (development of kindling induced seizure susceptibility) and those of the acute convulsive reaction to the epileptogen are not similar.     

16,16-Dimethyl prostaglandin E2 increases survival in mice following irradiation

16,16-Dimethyl prostaglandin E2 (DiPGE2), a stable analog of PGE2, increases the LD50/30 survival in CD2F1 male mice when given prior to ionizing radiation. Subcutaneous administration of 40 micrograms of DiPGE2 30 min prior to 60Co gamma irradiation extends the LD50/30 from 9.39 Gy in the control animals to 16.14 Gy in DiPGE2 treated, with a dose reduction factor of 1.72 [95% confidence limits: 1.62, 1.82]. The degree of protection is dependent on both the time of administration and the dose of the prostaglandin. Ten micrograms administered 5 min prior to receiving a lethal dose of 10 Gy provides 90% survival but only 10% survival if administered 30 min prior to irradiation. Experiments to determine the in vivo concentration of DiPGE2 in organs postinjection show increased levels over time, but these are not correlated with protection. At 30 min after injection, as much as 80% of the DiPGE2 present in the spleen and plasma is unmetabolized. These results suggest that the protection results from the physiologic action of DiPGE2 rather than direct in vivo detoxification of radicals.     

Effect of naloxone on GnRH-induced LH and FSH release in buffalo, Bubalus bubalis

The effect of naloxone on GnRH-induced LH and FSH release was measured in buffaloes in luteal phase of estrous cycle. Animals were administered intravenously, naloxone/saline (50 mg/injection) every 15 min for 3 hr followed by GnRH (100 micrograms). Peripheral plasma LH and FSH concentrations were measured in blood samples collected at 15 min intervals from 1 hr prior to beginning of naloxone/saline treatment up to 3 hr post GnRH administration and every 30 min for the subsequent 3.5 hr. Between the animals of Group I administered naloxone and those of Group II given saline, GnRH-induced peak LH and FSH concentrations, the total LH and FSH released in response to GnRH, and the time to peak LH and FSH concentrations were not significantly different. The results of the present study suggest the absence of a direct effect of naloxone on pituitary responsiveness to GnRH.     

Postoperative hypoparathyroidism: long term observation and therapy]

Hundred thirty patients with surgical hypoparathyroidism were followed up. Group I involved 45 patients with mild and group II--85 patients with severe surgical hypoparathyroidism. A delay in vitamin D3 therapy was X +/- SD = 4.2 +/- 8.1 years. A delay in introducing vitamin D3 therapy correlated with the duration of hypoparathyroidism (r = 0.93; 8.9 +/- 9.6 years). Follow up period lasted for 15 years and was 4.3 +/- 3.8 years out of which the attempts to establish ultimate and effective dose of vitamin D3 lasted 1.8 +/- 2.4 years. Dose of vitamin D3 was adjusted 5 times, on the average. Effective daily dose was 4,200-22,500 IU (9,311 +/- 7,252) in group I, and 30,000-195,000 IU (51,385 +/- 32,978) in group II whereas maximum daily dose was 75,000 and 250,000 IU respectively (p < 0.001). Some patients were given 25-OH-D3 in daily doses of 50-225 micrograms or 25(OH)2-D3 in daily dose of 0.10-0.75 micrograms. Calcium oral doses of 400-1600 mg daily were administered to 115 patients. In case of high hypercalciuria (over 350 mg/24 h) hydrochlorothiazide (43 +/- 17 mg a day) or chlorthalidone (60 +/- 22 mg a day) normalized calciuria. Low phosphate diet and aluminium oxide (4.4 +/- 1.7 g a day) were more frequently used in group II. Period of time necessary to establish an effective dose of vitamin D3 is long in patients with surgical hypoparathyroidism. Several dose adjustments are required. Maximum daily vitamin D3 dose required for normocalcemia is approximately higher by 1/3 in the early period of the treatment than the effective maintenance dose. A decrease in diet phosphate content, inhibition of phosphates absorption in the gut or blocking increased calcium loss with the urine are necessary in some patients, only.     

Effect of testosterone on testes, body weight and plumage regeneration in photorefractory male redheaded bunting Emberiza bruniceps

Various doses of testosterone propionate (TP) were administered for 10 days to refractory male redheaded buntings exposed to 15L:9D in last week of June, shortly before the onset of molt, to determine the effect of exogenous male hormone on the testes, body weight and plumage regeneration in photorefractory birds. While 5-, 10-, or 25 micrograms of TP bird-1 day-1 did not affect the testes, body weight or feather regeneration, testicular growth was stimulated but body weight declined and plumage regeneration prevented in birds that received 150- or 250 micrograms of TP bird-1 day-1. In contrast, a 50 micrograms treatment, although unable to induce the growth of the testes, caused loss in body weight and feather regeneration. Also, a 25 micrograms dose of TP administered to photostimulated birds induced complete testicular atrophy. These results suggests that testosterone exerts dose-dependent effects on the testes, body weight and plumage regeneration in buntings. A positive correlation is found between the amount of hormone and the testes growth, while the increasing amount of hormone has negative effect on the body weight and regeneration of feathers.     

The effect of AVP and DGAVP on the exploratory activity of rats

The effects of [8-L-arginine] vasopressin (AVP) and desglycinamide [8-L-arginine] vasopressin (DGAVP) were tested on the exploratory activity of adult male rats in a novel environment. The inherited individual differences in the non-specific excitability level of the animals were ascertained prior to the drug administration and the rats were then distributed evenly into the experimental groups. One half of each groups contained the less excitable and the other the more excitable animals. The peptides or saline were injected every other day--altogether 4 times--in a dose of 5 micrograms/kg/ml subcutaneously, 40 min before starting the experiments. The exploratory activity in the novel environment was observed for 15 min. AVP and DGAVP, which differ in their peripheral endocrine activities, had opposite effects on the behavior in a novel environment: AVP, with its wide spectrum of peripheral effects, decreased the exploratory activity, whereas DGAVP, with minimal peripheral effects, increased the exploratory activity slightly. This basic response to the administration of peptides was influenced by the type of inherent non-specific excitability level. The depressive action of AVP was more pronounced in the more excitable rats, whereas DGAVP significantly stimulated the less excitable animals. It is concluded that the inhibitory effect of AVP is mainly due to its peripheral endocrine, especially hemodynamic, effects, whereas DGAVP is supposed to increase arousal, which is responsible for differences in the animals' performance with regard to their inherited non-specific excitability levels.     

Protective effect of human epidermal growth factor against the experimental gastric mucosal lesions in rats

The protective effect of human epidermal growth factor (hEGF) on the gastric mucosal lesions in rats was examined in relation to the immunoreactive concentration of plasma. Human EGF (30 micrograms/kg) was administered intravenously, intraperitoneally or subcutaneously. At different times following the administration of hEGF, rats received acidified ethanol solution to induce an experimental gastric mucosal lesion. Sum of lesion length in the gastric mucosa was used as a lesion index. Human EGF administered parenterally markedly decreased the gastric mucosal lesions in 10 min after administration of necrotizing solution, and 10 to 30 min delay was observed in the development of maximal protective action. Profiles of protective potency against the hEGF dose administered intraperitoneally or subcutaneously 30 min before administration of necrotizing solution revealed that the effective dose of hEGF (ED50) was about 5.2 and 2.6 micrograms/kg, for intraperitoneal and subcutaneous administrations, respectively.     

Biological activity of a new Soviet natural inducer, double-stranded RNA

Antiviral activity of a two-spiral RNA (ts RNA), a new natural interferon inductor was studied. It was shown that ts RNA extracted from a phage infected E. coli culture was an active inductor of interferon and resistance to infection with the forestspring encephalitis virus experimental animals. In experiments on 10-12 g mice ts RNA administered in a dose of 50 micrograms/mouse 6 hours after the infection induced up to 1280 units/ml of the serum interferon. When the inductor was administered repeatedly, the experimental animals developed hyporeactivity resulting in a marked decrease in interferon production after the 3rd subsequent injection. The most pronounced effect with respect to the forest-spring encephalitis virus was observed when the inductor was administered intraperitoneally in a dose of 20 micrograms/mouse 4 hours before the infection. The protective effect was less pronounced when the inductor was administered 24 and 48 hours before the infection. A two-fold administration of the inductor did not increase the antiviral effect. When the inductor was administered in a dose of 100 micrograms 14 days before the infection, the animals showed an increase in the nonspecific resistance to the infection resulting in a marked antiviral effect.     

The significance of Na+ ions in angiotensin II stimulation of acquisition of active avoidance in rats

Angiotensin II (1 microgram) dissolved in water and given intracerebroventricularly on day 1, 15 min before the first learning session, enhanced rate of learning of active avoidance in rats over the next 7 days. However, the peptide, dissolved in 0.25 M NaCl, and given at the same dose and route, stimulated learning significantly more than that dissolved in water. A possible involvement of Na+ ions in facilitating learning action of A II is discussed.     

Male accessory gland secretory proteins in nasuta subgroup of Drosophila: nature and SDS-PAGE patterns

Male accessory gland secretory proteins in seven members of Drosophila nasuta subgroup were analyzed by SDS-PAGE in combination with different staining techniques such as CBB-R250, Silver, PAS, PAS-silver and zinc-imidazole reverse staining. Based on coomassie blue patterns the protein fractions could be classified in to 3 major groups namely group I, group II as well as group III; with high molecular weight fractions falling into group I and low molecular weight fractions into group III. All the three groups of fractions are post-translationally modified by way of glycosylation and group III fractions are found to be highly glycosylated. Fractions of groups I and II when localized with silver stain and group III fractions when localized with PAS-silver stain appear yellow; suggesting that they are sialoglycoproteins. A 40 kD fraction of group II shows differential staining property with zinc-imidazole stain in closely related species namely D. n. nasuta and D. n. albomicans. Analysis of this protein fraction in F1 males of an interspecific cross revealed that it is synthesized by X-chromosomal gene.     

Influence of semax on the emotional state of white rats in the norm and against the background of cholecystokinin-tetrapeptide action

The effects of the adrenocorticotropic hormone (ACTH(4–10)) analog, Semax (MEHFPGP), on the level of anxiety and depression in white rats have been studied in the normal state and against the back-ground of cholecystokinin-tetrapeptide (CCK-4) action. Semax was injected intranasally in doses of 50 and 500 μg/kg 15 min before the testing. CCK-4 was administered intraperitoneally in a dose of 400 μg/kg 40 min before the testing. The level of anxiety was estimated in the elevated plus-maze test, and the degree of depression, in the forced swimming test. Semax administration did not influence the emotional state of animals in the normal state. The CCK-4 injection led to an increase in anxiety and depression in rats. Semax normalized the animal behavior disturbed by the CCK-4 administration, which attests to its anxiolytic and antidepressant effects at elevated levels of anxiety and depression.     

Study of embryotoxic and teratogenic effects of amphotericin B and a methyl derivative of amphotericin B in rats after their intravenous and intra-amniotic administration]

The embryotoxic action of amphotericin B and its methyl derivative was compared in rats after their intravenous and intraamniotic administration. The concentrations of amphotericin B and its methyl derivative in the amniotic cavity on days 13, 14 and 15 of pregnancy were 1.5 and 36 micrograms/ml, respectively. When administered intravenously during the preimplantation period the antibiotics had no embryotoxic action. Intravenous administration of amphotericin B in a dose of 500 micrograms/kg and its derivative in a dose of 2000 micrograms/kg during organ genesis induced a decrease in the craniocaudal size. In a dose of 3000 micrograms/kg administered intravenously the methyl derivative of amphotericin B induced an increase in postimplantation death rates. Administration of amphotericin B to the amniotic cavity had no damaging action. Administration of the methyl derivative on day 15 of pregnancy led to anomalous development of the lower extremities and slower ossification. The threshold doses by the embryotoxic action for intravenous administration are 500 micrograms/kg for amphotericin B and 2000 micrograms/kg for the methyl derivative. Administration of the antibiotics to the amniotic cavity revealed potential teratogenic properties of the amphotericin B methyl derivative.     

Effect of prostaglandin F2 alpha on temperature and behaviour of centrally sympathectomized rats

Prostaglandin F2 alpha (PG F2 alpha) in doses of 1 and 10 micrograms applied intraventricularly causes a rise in body temperature and exerts a sedative action on rat behaviour. Chemical sympathectomy of the central nervous system (CNS) induced by a twofold intraventricular administration of 250 micrograms of 6-hydroxydopamine reduces the influence of PG F2 alpha on the body temperature and behaviour. Reserpine administered to rats with chemical sympathectomy of the central nervous system reverses or prevents the PG F2 alpha action on body temperature of the animals. The results of the experiments seem to indicate that the central monoaminergic mechanisms play a role in the central action of PG F2 alpha on body temperature and behaviour.     

Field immobilization and euthanasia of American opossum

Seventeen recently trapped opossum, Didelphis virginiana, (median weight 2.45 kg; range = 1.6-5.0 kg; quartiles = 1.8-3.3 kg) were immobilized with either telazol (15 or 30 mg/kg) or a mixture of medetomidine (100 micrograms/kg), butorphanol (0.2 mg/kg), and ketamine HCl (10 mg/kg) based on estimated weights. Anesthetized animals were subjected to cardiac puncture for blood withdrawal and toe pinch. Euthanasia was accomplished by intracardiac administration of 1 ml of concentrated pentobarbital sodium/phenytoin solution. Weights were underestimated for 14 of 17 animals, but were within 0.5 kg of the actual weight. Both drug combinations provided rapid and calm immobilization. Median time to recumbency for the medetomidine-butorphanol-ketamine group (n = 5) was 6 min (range = 4-10 min; quartiles = 6 and 8 min). The median time to recumbency was not statistically different for the low (n = 6) and high dose (n = 6) telazol groups, 3 and 3.5 min respectively (quartiles 3; 3.5 and 4; 5.5 min). The stronger heart beat with telazol immobilization facilitated cardiac puncture. All five animals administered the medetomidine-butorphanol-ketamine mixture and three of six animals given the low telazol dose reacted to cardiac puncture. Only one of six animals given the estimated 30 mg/kg dose of telazol reacted slightly to cardiac puncture. We conclude that 30 mg/kg telazol provides sufficient immobilization and analgesia to allow accurate cardiac puncture of the opossum if the procedure is performed within 5 to 10 min of recumbency. Intracardiac administration of concentrated pentobarbital sodium/phenytoin solution followed by bilateral thoracotomy provides appropriate euthanasia suitable for field situations.     

Estrous cycle synchronization in dairy heifers with the prostaglandin analog alfaprostol (I)

The prostaglandin F(2alpha) analog (PGFA) alfaprostol was used in 277 cyclic dairy heifers for the purpose of estrous cycle synchronization. A dose of 5 mg was used in all the trials during spring 1979 and 1.5 mg 100 kg body weight were used during winter 1979/80. Animals were treated according to 3 schedules: two doses 11 days apart without prior examination (Schedule I), one dose without prior observation and a second dose 11 days later only for those animals that failed to show estrus after the first treatment (Schedule II) and one dose for animals not showing estrus after a 5-day observation period (Schedule III). Estrus synchronization was achieved with peak estrus activity occurring form 32 to 72 h after treatment in 95% of the responding animals. Of the animals treated according to schedules I, II and III, 93%, 100% and 100% showed synchronized estrus activities respectively. Conception rates in all trials, from insemination at observed heat (Schedules I, II and III) or from fixed time insemination at 48 and 72 h after the first or second treatments in schedules III and I, respectively, compared well with that of untreated contemporary controls with a range of 34.2 to 66.7% for animals in these trials, and an overall conception rate of 49.48% for treated and of 48.30% for control animals. This observation, together with the pregnancy rate at 60 days after breeding (78.30% for all treated animals and 73.50% for all untreated controls), indicates that alfaprostol had no adverse effects on fertility.