Early-age neutering of puppies and kittens (as early as 6-7 weeks of age) is increasing in popularity in the United States. This increase likely results from accumulating information on the safety of the procedure and lack of long-term adverse side effects. As veterinarians become comfortable and familiar with the procedure, they are likely to encourage more clients to consider early-age neuter...

To evaluate the effects of sex hormones on heart function and biochemistry, gonadectomy (GX) was performed in postpubertal male (M) and female (F) rats and compared with sham-operated controls (SH). The groups were MSH; MGX; MGX replaced with testosterone 3 mg/day s.c. (MGX + T), FSH, and FGX replaced with estrogen 2 mg/day (FGX + E), progesterone 0.4 mg/day (FGX + P), estrogen and progesterone...

Wexler BC: Effect of an oral contraceptive drug on nonarteriosclerotic male and female virgin rats vs arteriosclerotic, male and female breeder rats. Angiology 25: 197-227, 1974 Aoki K: Experimental studies on the relationship between endocrine organs and hypertension in spontaneously hypertensive rats. I. Effects of hypophyscctomy, adrenalectomy, thyroidectomy, nephrectomy and sympathectomy on...

Sex differences in growth hormone (GH) secretion in the rat are thought to be determined, to a large extent, by gonadal steroid-dependent sex differences in somatostatin (SRIH) secretion from neurones in the periventricular nucleus (PeN) which project to the median eminence (ME). The present study aimed to obtain direct evidence for sex differences and gonadal regulation of SRIH release within ...

Wexler BC: Effect of an oral contraceptive drug on nonarteriosclerotic male and female virgin rats vs arteriosclerotic, male and female breeder rats. Angiology 25: 197-227, 1974 Aoki K: Experimental studies on the relationship between endocrine organs and hypertension in spontaneously hypertensive rats. I. Effects of hypophyscctomy, adrenalectomy, thyroidectomy, nephrectomy and sympathectomy on...

Wexler BC: Effect of an oral contraceptive drug on nonarteriosclerotic male and female virgin rats vs arteriosclerotic, male and female breeder rats. Angiology 25: 197-227, 1974 Aoki K: Experimental studies on the relationship between endocrine organs and hypertension in spontaneously hypertensive rats. I. Effects of hypophyscctomy, adrenalectomy, thyroidectomy, nephrectomy and sympathectomy on...

This study investigated the importance of the male sex hormone testosterone on salt-induced hypertension, renal alpha(2)-adrenoceptor subtype distribution, and gene expression in salt-sensitive (SBH) male Sabra rats. Comparisons of blood pressure and renal alpha(2)-adrenoceptor subtype gene expression and receptor densities have been made among sham-operated rats, and gonadectomized rats treate...

Sexual selection theory proposes that males suffer reduced immune function and increased parasitism as costs of expressing sexual signals. Life-history theory proposes that females suffer the same costs because of inherent trade-offs between reproduction and self-maintenance. Mechanistically, each theory invokes an energetic tradeoff, although few experiments have directly compared these costs ...

After reproductive senescence or gonadectomy, changes occur in neural gene expression, ultimately altering brain function. The endocrine mechanisms underlying these changes in gene expression beyond immediate hormone loss are poorly understood. To investigate this, we measured changes in gene expression the dorsal striatum, where 17β-estradiol modulates catecholamine signaling. In human caudate...