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Biomedical subjects

K H Outch

Publications and source records attributed to K H Outch.

10 recordsLinked to original sources

Consistent capacity for adrenocortical response to ACTH administration in pigs.

The effect of ACTH administration on plasma cortisol concentrations in purebred and crossbred pigs was investigated. Pigs were given either 25 IU of ACTH or physiologic saline solution IM. Blood samples were collected immediately before and 1 hour after ACTH or saline solution administration. Administration of ACTH resulted in a significant (P less than 0.01) increase in plasma cortisol concentration compared with that resulting from administration of saline solution; mean values after ACTH administration were similar in both breed groups. In contrast, a fivefold range of differences was observed among individual pigs of the same age, sex, and body weight, irrespective of breed group. The type and magnitude of the adrenocortical response was consistent and repeatable in pigs over a 3-month period, suggesting that pigs have a consistent capacity for adrenocortical response to ACTH administration. Development of a dynamic test allowed the high and low responding extremes in a population to be detected. The most suitable dose of synthetic ACTH was established to be 50 IU, and the best time for blood sample collection was 60 minutes after ACTH administration. The classification of individual pigs as high or low responders was repeatable and was not affected by prior short-term exposure to ACTH.

Adrenocorticotropic Hormone↗

Variable androgen receptor levels in infertile men.

Labeled methyltrienelone was used to determine androgen receptor (AR) levels in cultured pubic skin fibroblasts in 40 infertile men with primary seminiferous tubule disorders and 18 normal men. LH pulse patterns and mean serum LH levels were also determined by blood sampling at 10-min intervals for 6 h. The infertile men and the normal men had similar mean receptor levels [mean, 28.1 +/- 2.0 (+/- SEM) and 24.8 +/- 1.8 fmol/mg protein, respectively]. However, 5 men with chromosomal disorders had a higher mean AR level (41.3 +/- 6.2 fmol/mg protein) than the normal men, and 5 of the remaining infertile men (14.2%) had receptor levels that were less than the minimum value in normal men. In men with idiopathic oligospermia, 19.0% had low receptor levels. Although mean serum FSH and testosterone levels were similar in the infertile men with low AR levels and in the normal men, mean LH levels were significantly elevated in this group (7.1 vs. 3.6 IU/L), the higher values being a result of increased LH pulse amplitude (mean, 5.6 vs. 2.8 IU/L). The LH-testosterone product (an index of androgen resistance) was also elevated in these men. When infertile men with low AR levels were matched with infertile men with normal receptor levels, the mean LH values were significantly elevated in the former, as was the LH-testosterone product. Testosterone values were similar in the two groups of men. After excluding subjects with chromosomal disorders, there were no significant correlations between AR levels and other indices of androgen action, such as semen volume, seminal fructose, or sex hormone-binding globulin levels. We conclude that AR levels are higher in patients with severe testicular failure associated with X-chromosome disorders. Also, AR defects were found in 19.0% of infertile men with idiopathic oligospermia. Finally, elevation of mean LH levels in men with seminiferous tubule disorders may reflect resistance to androgen action.

Adult↗

Type A, test performance and salivary cortisol.

Forty first year medical students, previously screened for the presence or absence of the Type A behavior pattern, collected saliva samples for four days leading up to the first major examination of their medical school course. It was observed that the day of the examination produced substantially different patterns of salivary cortisol concentrations for Type A and non-A subjects, depending on their level of performance. The Type A subjects who scored above the median on the examination showed higher concentrations of salivary cortisol than Type A subjects who scored below the median. The reverse of this pattern was found for non-A subjects. Visual analog scale ratings of subjective stress showed no behavior pattern effects and a very low correlation with the salivary cortisol concentrations. The results support the view that the occurrence of physiological arousal associated with the Type A behaviour pattern is intermittent and dependent on situational factors such as expectation of success and actual success. This is consistent with conceptualizing the Type A pattern as a strategy for resource allocation which may be elective, rather then the behavioural manifestation of an automatic physical response to stress.

Achievement↗

Incidence of a heterosis effect in adrenal responsiveness to ACTH stimulation in the chicken.

No differences exist between basal plasma corticosterone concentrations of broilers ferals and first generation large crossbreds (White leghorn x New Hampshire). Crossbreds show near double adrenal responsiveness to synthetic ACTH administration, indicating a heterosis effect for this characteristic. Extraction of chicken plasma with 30% aqueous polyethylene glycol solution eliminates the need for tedious and expensive pre-assay purification of plasma.

Adrenal Glands↗

Seasonal variation in plasma testosterone, luteinizing hormone concentrations and LH-RH responsiveness in mature, male rusa deer (Cervus rusa timorensis).

Plasma testosterone and luteinizing hormone (LH) concentrations in immobilized or yarded rusa stags (Cervus rusa timorensis) were investigated over a two-year period. Testosterone concentrations showed a minor elevation in autumn (May) and reached maximal levels in late winter-early spring (August) coinciding with the rut. Luteinizing hormone in plasma was only detectable from January to May. Maximal responsiveness of the pituitary-gonadal axis to LH-RH stimulation was recorded in August. The combination of Fentaz (fentanylcitrate and azaperone) and Rompun (xylazine hydrochloride) for immobilizing deer influences hypothalamic function.

Acclimatization↗

Changes in plasma levels of cortisol and corticosterone after acute ACTH stimulation in rusa deer (Cervus rusa timorensis).

Resting cortisol and corticosterone levels in immobilized mature rusa stags (Cervus rusa timorensis) and the influence of synthetic ACTH on the cortisol/corticosterone ratio (F/B ratio) were investigated. The basal concentration of cortisol was found to be 14.07 nmol/l (SD = 9.3, N = 15) and corticosterone was 3.79 nmol/l (SD = 2.3, N = 15). The cortisol/corticosterone ratio for the basal level was 5.31 (SD = 3.9, N = 15). After ACTH administration the cortisol/corticosterone ratio increased to 11.41 (SD = 5.4, N = 147) regardless of doses of ACTH administered to individual stags. The adrenal response to ACTH administration has a potential application for selection of deer most suitable for deer farming.

Adrenocorticotropic Hormone↗

Monitoring induction of ovulation by rapid radioimmunoassays of oestrogen and pregnanediol glucuronides.

To increase the sample-handling capacity for an induction of ovulation programme, direct urinary radioimmunoassays (RIA) for three steroid glucuronides, pregnanediol-3-glucuronide (Pd-3-G), oestrone-3-glucuronide (E1-3-G), and oestriol-16 alpha-glucuronide (E3-16-G), were established. Results obtained for urinary Pd-3-G measured by direct RIA show an excellent correlation (r = 0.98, N = 46) with those for urinary pregnanediol measured by gas-liquid chromatography. Estrone-3-glucuronide (E1-3-G) and estriol-16 alpha-glucuronide (E3-16-G) values, measured by direct RIA, closely paralleled the total urinary oestrogen measured fluorimetrically. Ovarian response to ovulation induction therapy can be monitored by observing the changes in the levels of E1-3-G in urine. Pre-ovulatory levels of urinary E3-16-G were found to be too low for use in this regard. Direct RIA for E1-3-G and Pd-3-G are recommended as reliable indices of ovarian function in the monitoring of patients receiving treatment for the induction of ovulation.

Animals↗