The effect of sex and sex hormones on the infection of rats by Trichinella spiralis

1972 ◽  
Vol 50 (5) ◽  
pp. 597-602 ◽  
Author(s):  
Sarojam K. Mankau ◽  
Raymond Hamilton
Keyword(s):  
Sex Hormones ◽  
Worm Burden ◽  
Testosterone Propionate ◽  
Marked Decrease ◽  
Trichinella Spiralis ◽  
Male Rats ◽  
Normal Male ◽  
Normal Males

Male hooded rats infected with Trichinella spiralis larvae had three times more larvae in the muscles than females. Gonadectomized males injected with stilbestrol had a lower worm burden than normal males. Gonadectomized females injected with testosterone propionate harbored far more worms than normal females. Stilbestrol administered to normal male rats caused a marked decrease in T. spiralis, while testosterone administered to normal females resulted in a significant increase in the number of parasites.

The Effect of Leptin on Sex Hormones and Antioxidant Enzyme Levels in Obese and Normal Male Rats

2018 ◽  
Vol 25 (3) ◽  
pp. 1105-1111 ◽  
Author(s):  
Hossein Cheraghi ◽  
Morteza Zendehdel ◽  
Jamshid GhiasiGhalehkandi ◽  
Parviz Tajik ◽  
Negar Panahi
Keyword(s):  
Antioxidant Enzyme ◽  
Sex Hormones ◽  
Male Rats ◽  
Normal Male

PREVENTION OF CENTRAL DEFEMINIZATION BUT NOT MASCULINIZATION IN MALE RATS BY INHIBITION NEONATALLY OF OESTROGEN BIOSYNTHESIS

1977 ◽  
Vol 74 (3) ◽  
pp. 375-382 ◽  
Author(s):  
J. T. M. VREEBURG ◽  
PAULA D. M. VAN DER VAART ◽  
P. VAN DER SCHOOT
Keyword(s):  
Sexual Function ◽  
Ovarian Function ◽  
Testosterone Propionate ◽  
Neonatal Period ◽  
Female Rats ◽  
Male Rats ◽  
Normal Male ◽  
Male And Female ◽  
Male And Female Rats ◽  
Copulatory Behaviour

SUMMARY An inhibitor of aromatization, androsta-1,4,6-triene-3,17-dione (ATD), was administered to newborn male and female rats and various parameters of gonadal and sexual function were examined in adulthood. Males injected with 1 mg ATD on the day of birth (day 1) and on days 3, 5, 10 and 15 postnatally, subsequently (day 55) showed normal male and female copulatory behaviour, but were not able to maintain cyclicity in ovarian transplants. When the ATD was administered by Silastic implants, however, cyclicity in ovarian transplants did occur. Neither form of treatment brought about significant changes in neonatal plasma or testicular testosterone concentrations. Female rats implanted on day 3 of life with Silastic capsules containing ATD and then given an injection of 0·25 mg testosterone propionate on day 5 subsequently showed normal ovarian function, whereas the controls receiving only testosterone propionate showed persistent vaginal cornification, anovulation and polyfollicular ovaries. The results support the view that the central conversion of testicular androgens to oestrogens during the neonatal period is necessary to abolish cyclic gonadotrophin release and to suppress female copulatory behaviour.

THE EFFECT OF HEPATECTOMY AND SEX HORMONES ON THE PSEUDOCHOLINESTERASE ACTIVITY IN LIVER AND SERUM OF THE RAT

1970 ◽  
Vol 65 (1) ◽  
pp. 184-192 ◽  
Author(s):  
R. S. Leeuwin ◽  
E. Th. Groenewoud
Keyword(s):  
Sex Hormones ◽  
Testosterone Propionate ◽  
Marked Decrease ◽  
Normal Values ◽  
Female Rats ◽  
Slow Increase ◽  
Male And Female Rats ◽  
Oestradiol Benzoate ◽  
Synthetic Capacity ◽  
Low Activity

ABSTRACT A study was made of the combined effects of hepatectomy, castration and treatment with sex hormones on the pseudocholinesterase activity in liver and serum of male and female rats. Hepatectomy in normal rats results in a sharp decline of the pseudocholinesterase activity, subsequently followed in females by a rapid increase to normal values and in males by a very slow increase. Hepatectomy in castrated rats also causes a marked decrease of the pseudocholinesterase activity, but the pseudocholinesterase activity remains at a relatively low level, in both castrated females and castrated males. Daily treatment of castrated-hepatectomized females with oestradiol-benzoate, either immediately or nine days after hepatectomy induces a gradual restoration of the enzyme activity to and above the normal castrate level. When castrated-hepatectomized males are treated daily with testosterone-propionate the extremely low activity may even be depressed further. These experiments once again stress the important role played by the liver and by sex hormones in the synthesis of the enzyme pseudocholinesterase. There was no evidence from our experiments that the steroid hormones affect the speed of regeneration of the liver as a whole. From this it must be decided that they only affect the restoration of the synthetic capacity for pseudocholinesterase. In all experiments the changes in liver pseudocholinesterase activity were reflected in the serum activity.

Inductive influence of testosterone upon central sexual maturation in the rat

Development ◽  
1967 ◽  
Vol 17 (1) ◽  
pp. 171-175
Author(s):  
W. N. Adams Smith ◽  
M. T. Peng
Keyword(s):  
Corpus Luteum ◽  
Sex Hormones ◽  
Adult Male ◽  
Sexual Maturation ◽  
Male Genitalia ◽  
Testosterone Propionate ◽  
Single Injection ◽  
Male Rats ◽  
Corpora Lutea

The influence of the testis and of testosterone upon the development of the male genitalia has been extensively investigated and a number of reviews of this work have been published (Jost, 1960; Burns, 1961). However, Witschi (1957) has stressed the need to distinguish between adult sex hormones, such as testosterone, and the secretions of the immature gonad. The formation of corpora lutea in the ovaries transplanted to adult male rats which had been castrated at birth, and the absence of corpus luteum formation in ovaries transplanted to male hosts bearing transplanted testes in the neck from birth, was reported by Pfeiffer in 1936. Similar observations have been reported by Yazaki (1960) and Harris (1964). A single injection of testosterone propionate has been found to lead to permanent sterility and a loss of corpus luteum formation in the ovaries of mice (Barraclough & Leathern, 1954) and rats (Barraclough, 1961).

Sex Hormones and Phytomenadione Evidence for their Relationship in an Induced Coagulation Defect

1975 ◽  
Author(s):  
J. H. Sanderson ◽  
I. S. Chart ◽  
C. Shingles
Keyword(s):  
Sex Hormones ◽  
Sex Differentiation ◽  
Male Rats ◽  
Normal Male ◽  
Coagulation Defect ◽  
Dose Levels

Rats dosed with benzyl 3,5-dichloro-2,6-difluoro-2-pyridyl ether show a coagulation defect which is much more severe in males than females, and dose levels can be chosen at which males only are affected. The defect is produced by a lowering of Factors VII X and II.This sex differentiation can be abolished if male rats are castrated or if they are treated with oestrogens, and normal male rats can be protected by treatment with Phytomenadione.It is suggested that the use of this compound may provide a tool for understanding mechanisms of anti-coagulation.

THE EFFECT OF A SINGLE NEONATAL SEX HORMONE INJECTION ON THE GROWTH OF THE RAT PELVIS

1974 ◽  
Vol 77 (3) ◽  
pp. 612-624 ◽  
Author(s):  
P. C. R. Hughes ◽  
J. M. Tanner
Keyword(s):  
Sex Differences ◽  
Testosterone Propionate ◽  
Sex Hormone ◽  
Male Rats ◽  
Hormone Injection ◽  
Males And Females ◽  
Normal Males ◽  
Pelvic Size

ABSTRACT On the 26th day post-copulation (p. c.) male rats were injected with 100 μg Hexoestrol® and females were injected with 1.25 mg testosterone propionate. The growth of the pelvis of these animals was then measured from radiographs taken longitudinally from 23 days p. c. until 140 days p.c. Generally the effect of neonatal sex hormone injection was to diminish, but not abolish, the sex differences in pelvic size. The magnitude of the effect differed according to measurement and sex. Thus ilium length was diminished more in males than it was augmented in females, while ischial length and bi-acetabular width were only slightly diminished in males but considerably increased in females. The effects were greatest in bi-iliac width where both treated groups came to be exactly intermediate between normal males and females.

THE EFFECTS OF NEONATAL ANDROGEN ADMINISTRATION ON THE AGGRESSION AND RELATED BEHAVIOUR OF MALE GOLDEN HAMSTERS DURING INTERACTIONS WITH FEMALES

1973 ◽  
Vol 58 (3) ◽  
pp. 627-636 ◽  
Author(s):  
A. P. PAYNE ◽  
H. H. SWANSON
Keyword(s):  
Aggressive Behaviour ◽  
Testosterone Propionate ◽  
Adaptive Significance ◽  
Normal Male ◽  
Neonatal Development ◽  
Male Hamster ◽  
Golden Hamsters ◽  
Normal Males ◽  
Male Golden Hamsters

SUMMARY Male golden hamsters received either 300 μg testosterone propionate or oil on day 1 of life. As adults they were observed (i) when intact (ii) when castrated and (iii) when receiving 1 mg testosterone propionate per day in interactions with intact dioestrous females. Male controls which had received oil neonatally resembled normal untreated males in showing less aggressive behaviour than females. Castration and subsequent androgen administration did not affect aggression in the controls. Conversely, neonatally androgenized males showed comparable levels of aggression to the females with which they interacted. Castration reduced aggressive behaviour in these males, while subsequent androgen administration resulted in them showing significantly more aggression than females. In particular, when intact or receiving androgen replacement, neonatally androgenized males attacked and bit females, a behaviour seldom seen in normal males or in those given oil neonatally. Sexual investigation and following decreased in both groups of males after castration, and increased under androgen replacement. These changes were more pronounced in the neonatally androgenized males, indicating a greater behavioural responsiveness to androgens in this group. It is suggested that the behaviour of the normal male hamster is incompletely 'masculinized' during neonatal development, and the possible adaptive significance of this is discussed.

EFFECTS OF DIHYDROTESTOSTERONE AND OESTRADIOL ON SEXUAL DIFFERENTIATION IN MALE RATS

1980 ◽  
Vol 84 (3) ◽  
pp. 397-407 ◽  
Author(s):  
P. VAN DER SCHOOT
Keyword(s):  
Sexual Differentiation ◽  
Testosterone Propionate ◽  
Neonatal Period ◽  
Combined Treatment ◽  
Female Rats ◽  
Male Rats ◽  
Normal Male ◽  
Oestradiol Benzoate ◽  
The Brain ◽  
Copulatory Behaviour

Adult male rats which had been castrated at birth and treated with the non-aromatizable androgen dihydrotestosterone propionate (DHTP) showed incomplete copulatory behaviour. When tested with oestrous female rats during treatment with testosterone propionate (TP) they readily mounted these females and showed frequent penile intromissions but rarely ejaculated. In a long series of observations the proportion of ejaculating rats in tests of 30 min did not exceed 50%. Neonatally castrated rats treated with DHTP during infancy thus seemed to be capable of ejaculation in adulthood during treatment with TP, but the threshold for the occurrence of the ejaculatory reflex seemed to be higher than in normal male rats. By replacing treatment in adulthood with TP by a combined treatment with DHTP and oestradiol benzoate (OB), the frequency of ejaculation was not increased. It was concluded that the incomplete copulatory behaviour was not due to reduced efficiency of aromatization of androgen within the brain of these rats. The addition of OB to DHTP during the neonatal period of treatment enhanced the frequency of ejaculation in adulthood. The combined treatment of 0·1 mg DHTP on days 1, 3 and 5 with 0·01 mg OB on day 1 made adult copulatory behaviour during treatment with TP indistinguishable from that of rats castrated on day 10 or rats castrated at birth and treated with TP during infancy. It was concluded that the masculine organization of systems and structures involved in the display of male copulatory behaviour occurs under the influence of both non-aromatizable androgen and oestrogen, oestrogen being most likely the substance required to 'organize' the central nervous aspects of the regulation of this behaviour. The absence neonatally of nonaromatizable androgen and/or oestrogen results in specific deficiencies in adult copulatory behaviour as compared with the behaviour of normal male rats.

THE INFLUENCE OF SEX HORMONES ON THE WEIGHT OF THE ADRENAL GLAND IN THE RAT

1956 ◽  
Vol 13 (2) ◽  
pp. 150-160 ◽  
Author(s):  
SHEILA B. CARTER
Keyword(s):  
Adrenal Gland ◽  
Sex Hormones ◽  
Adrenal Glands ◽  
Testosterone Propionate ◽  
Daily Treatment ◽  
Female Rats ◽  
Male Rats ◽  
Consistent Effect ◽  
Loss Of Weight

SUMMARY Experiments have been carried out to investigate the effect of sex hormones, particularly oestrogens, on the weight of the adrenal glands in rats. Female rats (a) Intact. Oestrogen had no consistent effect. The adrenal glands may become heavier after treatment with oestradiol dipropionate (ODP) for very short periods (3 days), but may become lighter after longer periods of treatment. The glands were lighter after treatment with testosterone propionate (TP) (1·5 mg daily). (b) Castrated. Fifty-three days after spaying the adrenal glands were unchanged. Seventy-five days after operation, their weight had decreased. Oestrogen had no effect when given 1 month after ovariectomy, but caused a loss of weight when treatment was started 2 months after the operation. TP (1·5 mg. daily) also caused a loss of weight. Male rats (a) Intact. The adrenal glands were unaffected by daily treatment with 1·5 mg TP, or with 100μg ODP. (b) Castrated. The adrenal glands had gained weight 53 days after orchidectomy. TP caused a loss of weight in castrated rats. ODP had no effect.

Short- and long-term effects of testosterone on diaphragm in castrated and normal male rats

1997 ◽  
Vol 82 (1) ◽  
pp. 134-143 ◽  
Author(s):  
David J. Prezant ◽  
Manoj L. Karwa ◽  
Helen H. Kim ◽  
Diane Maggiore ◽  
Virginia Chung ◽  
...  
Keyword(s):  
Serum Testosterone ◽  
Male Rats ◽  
Normal Male ◽  
Type Ii ◽  
Long Term Effects ◽  
Testosterone Levels ◽  
Diaphragm Function ◽  
Short And Long Term ◽  
Normal Males

Prezant, David J., Manoj L. Karwa, Helen H. Kim, Diane Maggiore, Virginia Chung, and David E. Valentine. Short- and long-term effects of testosterone on diaphragm in castrated and normal male rats. J. Appl. Physiol. 82(1): 134–143, 1997.—The effects of short- and long-term testosterone absence or treatment on the diaphragm were studied in castrated and sexually normal male rats. Compared with control rats (untreated normal males), testosterone absence or treatment did not significantly affect costal weight. In untreated castrated males, there were significant decreases in specific forces, type II fiber cross-sectional area, and myosin heavy chain (MHC) isoform 2B after 2.5 wk. In castrated males that received testosterone, there were significant increases in specific forces, type II total fiber proportional area, and relative expression of all adult diaphragm fast MHC isoforms (MHC-2all) after 2.5 wk. In normal males that received testosterone, the only significant finding was an increase in MHC-2B after 2.5 wk. Across all groups, there was close correlation between increases in maximum tetanic forces and MHC-2all. Changes in diaphragm function and composition were closely related to changes in serum testosterone levels at 2.5 wk. The lack of significant change in diaphragm function at 10 wk occurred despite changes in serum testosterone levels and diaphragm composition similar to those at 2.5 wk. These findings support our hypothesis that the effects of testosterone are dependent on basal circulating androgen levels and study duration.

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