Ten male advanced meditators and ten male long-term meditators subjected themselves four times to slight physical exercise following a period of rest, meditation or reading. Daily urine excretions of catecholamines and VMA were determined in both groups. On the experimental days 4-hour urine specimens, one before and one after the experiments, were again collected for analysis. During the experiments blood pressure and heart rate were measured continuously and blood samples were taken for plasma catecholamine levels immediately before and after the physical exercise. Daily catecholamine and VMA excretions showed to be higher in advanced meditators. During the experiments the pattern of noradrenaline, adrenaline and VMA excretions were different in both groups, long-term meditators showing a higher adrenaline excretion after exercise. After the resting period there was in both groups a similar increase of plasma catecholamine levels during exercise. However, after meditation the advanced meditators showed a significant increase in plasma noradrenaline and no further increase in plasma noradrenaline level during the following physical exercise. Also after the reading period differences between both groups in plasma catecholamine levels during exercise could be observed. In advanced meditators heart rate reduction after meditation was about 9% and diastolic blood pressure was slightly raised. The preceding conditions of rest, meditation or reading had a significant different influence on the behaviour of heart rate and blood pressure during the following physical exercise and this pattern was different for both groups.

Four streptozotocin-diabetic gilts (maintained on exogenous insulin for 3 months) and 4 normoglycaemic gilts were treated with 600 i.u. PMSG. Diabetic gilts had insulin therapy removed at the time of PMSG administration. Plasma glucose averaged 463 +/- 5 mg/100 ml for diabetic gilts and 82 +/- 4 mg/100 ml for control gilts over the 72-h sampling period. Serum insulin was lower in diabetic than in normoglycaemic gilts (glycaemic state by time interaction; P less than 0.0001). At ovary removal 75 h after PMSG, numbers and percentages of large (greater than or equal to 7 mm) and medium (3-6 mm) non-atretic follicles were similar for diabetic and control gilts (31 vs 68%; s.e.m. = 7; P less than 0.05). Diabetic gilts had a greater percentage of atretic follicles over all size classes (50 vs 21%; s.e.m. = 7; P less than 0.03). After PMSG, LH was suppressed within 12 h in control gilts and remained similar to values in diabetic gilts until 72 h, when LH was elevated in 2 diabetic gilts (glycaemic state by time interaction; P less than 0.001). Pulsatile LH patterns during 52-55 h after PMSG were not affected by glycaemic state. Serum concentrations of IGF-I tended (P less than 0.1) to be lower in diabetic gilts. Concentrations of oestradiol and FSH in serum were similar in diabetic and control gilts. Follicular fluid concentrations of oestradiol in follicles greater than or equal to 7 mm were lower in diabetic than normoglycaemic gilts (341 vs 873 ng/ml; s.e.m. = 86; P less than 0.05). Testosterone was higher in follicles 3-6 mm in diameter in diabetic than in normoglycaemic gilts (142 vs 80 ng/ml; s.e.m. = 26; P less than 0.05). Progesterone concentrations in follicular fluid were not affected by glycaemic state. Concentrations of IGF-I in follicles greater than or equal to 7 mm were lower in diabetic than control gilts (150 vs 200 ng/ml; s.e.m. = 13; P less than 0.05). We conclude that follicles of diabetic gilts respond to external gonadotrophic stimulation with decreased hormone production and increased ovarian follicular atresia, despite an absence of effects on circulating gonadotrophin and oestradiol concentrations.

Development of preovulatory follicles was studied during the oestrous cycle in two experiments designed to examine the effects of short-term lack of insulin on preovulatory follicular function and (Expt 2 only) ovulation. In Expt 1, on day 12 of the third postpubertal oestrous cycle, insulin treatment was discontinued in streptozocin-induced diabetic gilts (n = 4), and on day 18, ovaries were removed from the diabetic gilts and from four normal untreated gilts. Diabetic gilts had a higher percentage of macroscopically atretic follicles (29.4 versus 6.8%; SEM = 5.9, P < 0.03) than did normal gilts. Binding of 125I-labelled hCG by freshly collected granulosa cells from non-atretic follicles was similar in diabetic and normal gilts. Diabetic gilts had more LH peaks in 3 h on days 12-17 of the oestrous cycle than did normal gilts (2.3 versus 1.6; SEM = 0.12; P < 0.01). Serum oestradiol and progesterone concentrations were not affected by treatment, but serum testosterone was increased (P < 0.01) in diabetic gilts. In Expt 2, insulin treatment was withdrawn from nine diabetic gilts on day 12 of the oestrous cycle and ten normal gilts served as controls. On day 18, ovaries were removed from six diabetic and six normal gilts; four normal and three diabetic gilts were ovariectomized 25 days after oestrus. Follicular diameter of diabetic gilts tended to be smaller than that of control (control: 3.95 versus diabetic: 3.01 mm; SEM = 0.4, P < 0.08) and the proportion of follicles with histologic evidence of atresia was higher in diabetic gilts (control: 29 versus diabetic: 47%; SEM = 5; P < 0.05) on day 18. In both experiments, the insulin-like growth factor I (IGF-I) and oestradiol concentrations of follicular fluid of diabetic gilts untreated with insulin from day 12 to day 18 was lower than in nondiabetic gilts. After day 18 in Expt 2, normal gilts exhibited oestrus (duration of cycle was 20 +/- 0.5 days) accompanied by preovulatory surges in oestradiol and LH, whereas diabetic gilts did not exhibit oestrus or ovulate. In diabetic gilts, oestradiol concentrations were lower compared with those of normal gilts, and LH patterns were characterized by two (two gilts) or three (one gilt) increases of more than 2 ng ml-1 between day 18 and day 25. Thus, impaired follicular function in diabetic gilts is not explained by decreased function of the hypothalamo-pituitary axis, since LH was not decreased.(ABSTRACT TRUNCATED AT 400 WORDS)

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