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Biomedical subjects

B Robinzon

Publications and source records attributed to B Robinzon.

At least 55 records · Page 3Linked to original sources
PubMed1990

The response of broilers' adiposity to testosterone after embryonic exposure to androgen and tamoxifen.

1. The effects of early exposure of heavy breed (HB) chicks to an anti-oestrogen (tamoxifen--TAM) and to an androgen which cannot be aromatised (5 alpha-dihydrotestosterone--DHT) on subsequent adiposity and its response to testosterone were studied. 2. Embryonic TAM administration reduced adiposity in females but not in males at 8 weeks of age. Embryonic DHT produced similar responses but to a lesser extent. 3. Testosterone propionate (TP) administration during growth had no effect on adiposity in any of the treated groups but TP reduced adiposity in males which had been exposed to DHT at the embryonic stage.

Adipose Tissue↗
PubMed1990

Arginine vasotocin and mesotocin in the anterior hypothalamus, neurohypophysis, proventriculus and plasma of White Leghorn cockerels, during dehydration.

1. The effect of 96 hrs of water deprivation on plasma electrolytes, osmolarity, arginine vasotocin (AVT), mesotocin (MT), and on AVT and MT content in the neurohypophysis, anterior hypothalamic area (AHA) and proventriculus, was studied at 24 hrs intervals, in adult White Leghorn cockerels. 2. Plasma AVT increased three fold during the first 24 hrs but there was no further change during the next 48 hrs. In the last 24 hrs, plasma AVT decreased in about 25%. Plasma MT did not change during the entire period of dehydration. 3. Plasma sodium and osmolarity gradually increased during that time. 4. Neurohypophysial AVT content was depleted by 95% during the period of dehydration while MT content did not change. 5. In the AHA there was no change in AVT levels during dehydration while the levels of MT increased while in the proventriculus there was no change in either AVT or MT levels. 6. For the data collected during the entire experimental period, no correlation was found between plasma osmolarity and plasma AVT, but there was a highly significant negative correlation between plasma osmolarity and neurohypophysial AVT content. 7. It may be suggested that the depletion in AVT content in the neurohypophysis during progressive water deprivation resulted in an insufficient level of AVT in circulation to enable the cockerels to counter the dehydration. This may explain the death of those cockerels which were dehydrated for a further 24 hr period.

Animals↗
PubMed1990

Effects of sex and gonadal steroids on arginine vasotocin and mesotocin in the pineal gland and neurohypophysis of White Leghorn fowls.

1. Pineal and neurohypophysial arginine vasotocin (AVT) and mesotocin (MT) were measured in White Leghorn hens, cockerels and castrated males treated with either testosterone propionate (TP) or oestradiol benzoate (EB) (n = 10/group). The lighting regimen was 14 h light: 10 h dark, supplied by natural diffused sunlight and incandescent bulbs. 2. Both AVT and MT were detected in the pineal gland of all the chickens. 3. There was no significant effect of either sex or treatments on pineal MT. 4. Females had about 4 times more pineal AVT than males, regardless of their treatment. There was no effect of the treatments on pineal AVT in the males. 5. No sexual difference in neurohypophysial AVT was detected, but the neurohypophysis of the castrated males treated with EB contained less AVT than the neurohypophysis of the intact males. 6. Intact males had about twice as much MT in the neurohypophysis as females. Castrated males treated with either TP or EB had similar concentrations of neurohypophysial MT, which were lower than that of the intact males, but higher than that of the females.

Animals↗
PubMed1990

The effect of tamoxifen on sexual puberty of turkey toms and Muscovy drakes.

The effects of Tamoxifen (TAM) on reproductive traits in young turkey toms and Muscovy drakes were studied. At 6 wk of age, five toms were injected every other day with 1 mg TAM/kg BW, while six others were treated with corn oil (controls). In the toms, using TAM advanced semen production by 4 wk (13.5 versus 17.5 wk of age) and increased the size of the snood and testes. Similarly, in the Muscovy drake, using TAM enhanced penis growth and advanced semen production by 5 wk.

Animals↗
PubMed1990

The effect of tamoxifen on semen fertilization capacity in White Leghorn male chicks.

Tamoxifen (TAM) is an antiestrogen that advances sexual puberty in cockerels, turkey toms, and Muscovy drakes. The effect of TAM on semen-fertilization capacity in White Leghorn (WL) male chicks was assayed in the present study. Sixty, 2-wk-old, male chicks were divided into two equal groups. The chicks from one group were injected im with 1 mg of TAM per kg of BW every other day; those from the second group were vehicle-treated (with corn oil) and served as controls. Each chick was paired with a virgin, WL laying hen. When semen was produced, the paired female was inseminated twice a week. The results revealed that TAM administration caused the early production of fertile semen, which resulted in the first normal descendants as early as 8 wk of age and brought about 100% of parenthood by the age of 88 days.

Animals↗
PubMed1989

Embryonic sex steroids affect mating behavior and plasma LH in adult chickens.

Chicken embryos of both sexes were treated with either antiestrogen (tamoxifen = T), antiandrogen (flutamide = F), aromatization inhibitor (ATD = A), estradiol (E), or oil (control = C). Before puberty, some males of each group were castrated. At puberty, birds were tested under the following regimes: castrated males injected daily with testosterone propionate (CAS + TP) or estradiol benzoate (CAS + EB), intact males (M-INT), intact females (F-INT), and females injected daily with TP (F-TP). In the M-INT and CAS + TP males, E treatment suppressed masculine mating behavior. The embryonic treatments with T, F, and A demasculinized only the frequency of copulations. None of the antihormone treatments caused any masculinization of the sexual activity in the F-TP birds. Untreated males had higher plasma LH than females. The embryonic treatment with E reduced (feminized) the LH levels in CAS + EB birds. This effect was less pronounced in M-INT birds. The results suggest that in chickens, estradiol plays a role in the masculinization of copulatory behavior potential in the developing male embryo. High embryonic estradiol reduces the potential for displaying male sexual behavior at puberty. Feminization of LH secretion requires a high level of estradiol in both embryonic and adult life.

Androstatrienes↗
PubMed1989

The effect of tamoxifen on the reproductive traits in White Leghorn cockerels.

Fifty White Leghorn male chicks were divided into five equal groups of ten chicks each. Beginning at two weeks of age they were injected on each alternate day as follows: corn oil as a vehicle control or 0.5, 1.0, 5.0, or 10.0 mg tamoxifen/kg/b.wt. The whole experimental period lasted until twelve weeks of age. The two lowest doses of tamoxifen (TAM) enhanced comb growth, while the highest dose suppressed it. The two lowest doses of TAM also caused an earlier increase in sexual activity of the chicks, and precocious production of semen. At nine weeks of age the 0.5 and 1.0 mg doses of TAM increased plasma testosterone to a level three times higher than in the controls. This effect was not observed with the highest dose of TAM. At 12 weeks of age the chicks treated with 1 mg TAM had larger testes than the controls and produced three times more sperm per ejaculation. At this stage chicks treated with the highest dose of tamoxifen produced less sperm than the control and had smaller testes and adenohypophyses.

Aging↗
PubMed1989

Effect of embryonic and neonatal administration of tamoxifen on adiposity in the broiler chicken.

1. The effect of early exposure of heavy breed (HB) chicks to an anti-oestrogen (tamoxifen--TAM) on later adiposity was studied. 2. TAM administration at the embryonic stage, but not at the day of hatching, reduced adiposity in females but not in males, at 8 to 9 weeks of age. This reduction in adiposity in females minimised or even alleviated the excess of fat in females compared to males.

Adipose Tissue↗
PubMed1989

Recovery of ova and their re-insertion into the hen's oviduct through a fistula.

1. The first loop of the domestic hen's magnum was fistulated. A cannula mounted with a collecting tube served to trap the passing ova about 2.5 h following ovulation. 2. Nine out of 10 fistulated hens resumed ovulation about 2 to 5 weeks following surgery. A total of 63 magnal ova were collected. 3. Five of the magnal ova were successfully returned to the oviduct through the fistula and resulted in 5 normal soft-shelled eggs. The success of ova reimplantation was affected by prolapse of the posterior part of the oviduct and the timing of ova return.

Animals↗
PubMed1989

Role of the basomedial hypothalamus in regulation of adiposity, food intake, and reproductive traits in the domestic fowl.

Bilateral basomedial hypothalamic (BMH) electrolytic lesions in White Leghorn cockerels produced six main physiological categories characterized by typical sets of symptoms: 1) functional castration (FC); hyperphagia, obesity, occasional diabetes insipidus, involuted adenohypophysis, dwarfism, atrophied comb and testes, reduced hematocrit, reduced plasma testosterone and thyroid activity, involuted thymus and adrenal cortex and elevated liver fat and plasma triglycerides and free fatty acids. The FC birds demonstrated defective immune response for the first 12 to 16 wk post-surgery. 2) functional castration with large comb (FCLC); hyperphagia, obesity, transient diabetes insipidus, slight diminution of adenohypophy-seal weight with marked reduction in basophilic cell population, fully atrophied testes but only slight reduction in comb size and hematocrit, plasma testosterone levels between those found in the first category and the control. 3) obese with normal testes (ONT); hyperphagia, obesity, high level of plasma lipids, normal histological organization of the adenohypophysis, normal testes, semen production and comb size. The next three categories exhibited physiological syndromes identical to the former three categories except for food intake, which operationally could be defined as normal. A marked difference among the BMH-lesioned birds was found in sexual behavior when the FC birds completely lost their libido. None of the replacement therapy regimens caused complete rehabilitation from adiposity or restoration of reproductive traits. Lipoprotein lipase activity increased at an early stage postlesioning and preceeded the development of hyperphagia. Placement of BMH lesions in newly hatched chicks resulted in marked dwarfism and obesity without hyperphagia. The BMH-lesioned heavy breed White Rock cockerels exhibited a lesser degree of adiposity than the light White Leghorn birds. Removal of the olfactory bulbs and destruction of the septal area resulted in increased thyroid activity, with secondary hyperphagia without obesity. In a short-term study, administration of sodium pentobarbital to the BMH area resulted in increased feeding. Conversely, glucose administration to the same area suppressed feeding in satiated but not in food-deprived chickens.

Adipose Tissue↗
PubMed1988

Human basophil degranulation triggered by very dilute antiserum against IgE.

When human polymorphonuclear basophils, a type of white blood cell with antibodies of the immunoglobulin E (IgE) type on its surface, are exposed to anti-IgE antibodies, they release histamine from their intracellular granules and change their staining properties. The latter can be demonstrated at dilutions of anti-IgE that range from 1 x 10(2) to 1 x 10(120); over that range, there are successive peaks of degranulation from 40 to 60% of the basophils, despite the calculated absence of any anti-IgE molecules at the highest dilutions. Since dilutions need to be accompanied by vigorous shaking for the effects to be observed, transmission of the biological information could be related to the molecular organization of water.

Antibodies, Anti-Idiotypic↗
PubMed1988

The effect of electrolytic lesions in the baso-medial-hypothalamus on the immune response of the chicken.

Electrolytic lesions of the baso-medial-hypothalamus (BMH) cause numerous dysfunctions of the endocrine system, many of which have been implicated in regulating immune responses. The objective of this report was to evaluate the direct effects of electrolytic lesions in the BMH on the immune response of the chicken. Our results indicate that temporary immune response impairment, as evaluated by both T and B lymphocyte related responses, occurred only in birds that expressed both brain damage and endocrine dysfunction, whereas birds expressing brain damage alone had normal immune responses. The possible regulation of immune responses by the BMH via the endocrine system is discussed.

Animals↗
PubMed1988

Distribution of immunoreactive vasotocin and mesotocin in the chicken gastrointestinal tract.

Immunoreactive arginine vasotocin (AVT) and mesotocin (MT) were measured in heart, breast muscle, adrenals, testes, and different parts of the gastrointestinal tract in adult male chickens. Neither of the peptides were detected in liver, testis, heart and breast muscle. The amounts of AVT and MT in the adrenals were 167 +/- 25 and 669 +/- 198 pg/gland, respectively. Considerable amounts of immunoreactive peptides were found in the gastrointestinal tract with the highest concentration in the proventriculus (4.18 +/- 0.31 ng AVT and 16.58 +/- 0.86 ng MT per organ). Dose-response curves of duodenal and proventriculus extracts were parallel with synthetic AVT and MT standards.

Animals↗
PubMed1988

Physiological effects of arginine vasotocin and mesotocin in cockerels.

1. The effects of continuous infusion of 0.1, 1.0 and 10.0 mU/min/kg body weight of arginine vasotocin (AVT) or mesotocin (MT) on cardiovascular and thermoregulatory responses, on plasma osmolality and ionic composition and on plasma concentrations of AVT, MT, prolactin and aldosterone, were investigated in conscious White Leghorn cockerels. 2. Neither of the peptides, at any dose, affected cardiovascular functions, plasma ions and osmolality. Infusion of MT at the rate of 10 mU/min/kg body weight increased respiratory rate. Both peptides at doses of 1 and 10 mU/min/kg reduced the temperatures of the comb and shank but had no effect on the skin and cloaca. 3. Doses of 0.1 and 1.0 mU MT/min/kg reduced plasma aldosterone and at 10 mU/min/kg increased plasma AVT. At any given dose MT had no effect on plasma prolactin. AVT at 0.1 and 1.0 mU/min/kg of AVT reduced plasma MT. AVT at 1.0 mU/min/kg increased plasma prolactin and at 10 mU/min/kg reduced plasma aldosterone. 4. During saline infusion, plasma MT was positively correlated with plasma AVT and negatively correlated with respiratory rate and cloacal temperature. Plasma AVT showed a positive correlation with plasma MT and aldosterone and a negative correlation with respiratory rate and skin temperature. 5. During saline infusion, there was no significant correlation between cardiovascular functions, or plasma osmolality and ionic composition and plasma MT or AVT. 6. The present study suggests that interrelationships between circulating concentrations of AVT and MT do exist and that AVT affects aldosterone secretion. These neurohypophysical peptides are involved in thermoregulation.

Aldosterone↗
PubMed1988

Fertile semen from 9-week-old chicks treated with tamoxifen.

White Leghorn male chicks were injected with 1 mg/kg BW of tamoxifen (an anti-estrogen) on alternating days between 2 and 9 wk of age. This treatment increased testes weight and induced semen production in response to the abdominal massage procedure. Insemination of laying hens with this semen resulted in hatching of live chicks from their eggs.

Animals↗
PubMed1987

Testosterone and adiposity in the chicken: the effect of breed and sex.

The leaning role, previously suggested for testosterone in chickens, was tested in males and females of fatty and lean breeds. The breeds used were the White Leghorn (WL), of which the male is very lean, and the White Giant (WG) and the White Cornish X White Rock (WCWR), in which both sexes accumulate fat. Castration of WL males induced adiposity and replacement therapy with testosterone propionate (TP) reduced the fat to normal. However, in males of the fatty breeds, neither castration nor TP administration had any effect on adiposity. Similarly, long-term supplementation of a high dose of TP had no effect on the level of adiposity in females of both the heavy and the light breeds. Thus, the leaning effect found for testosterone in the WL male is not a general phenomenon in chickens but rather a specific response of the WL male.

Adipose Tissue↗
PubMed1987

Application of the filial imprinting phenomenon to broiler chicks at a commercial farm.

Ten thousand broiler chicks on commercial farms in Israel were imprinted to blue and red plastic boxes (20 x 20 x 40 cm) containing loud speakers (8 omega, 12 W) equipped with a tape recorder, in which a classical music cassette had been placed. Upon reaching 3 wk of age, an attempt was made to move these chicks from the training area (A) to a new area (B) using the imprinting objects. This experiment was repeated four times: May, August and November of 1985, and in January 1986. During the warm months of May and August 30 to 60% of the experimental chicks followed the imprinting objects toward Area B. During the cold months and in all four repetitions with the controls, less than 5% of the flocks moved from Area A to Area B. Winter chicks may have been imprinted on brooder heaters. In all repetitions, most of the imprinted chicks distributed themselves equally over Area B 1 h after the doors between Areas B and A were closed. Controls, however, crowded around the door between Areas A and B resulting in the death of many chicks by asphyxiation. This study has shown that thousands of heavy strain chicks can be easily attached to an imprinting stimulus and it may be possible to apply this phenomenon for commercial purposes.

Acoustic Stimulation↗