Stress from exercise in the below sea level environment causes an increase in serum testosterone levels in trained athletes.

A comparative study (n = 20) of serum levels of leutinizing hormone (LH) and testosterone (T) between male trained athletes (high-school students, 16-18 years old) living in North and South Shouna in the Jordan Valley (JV), 320-360 meters below sea level, and those living in Ramtha and Irbid, 550-650 meters above sea level, was conducted in November, 1999. Serum levels of LH and T were also measured in these athletes following a 20 Km noncompetitive run. The air temperatures on the day of the experiment was comparable (25 degrees C in North and South Shouna versus 23 degrees C in Ramtha and Irbid). Before exercise, serum levels of LH and T in athletes of the below sea level environment (North and South Shouna) were similar to those levels in athletes of the above sea level environment (Ramtha and Irbid). Exercise caused a significant increase in serum levels of both LH and T only in athletes of North and South Shouna. It seems likely that the higher secretion of LH contributes, at least in part, for the higher serum levels of T following exercise. Taken together, these data suggest that exercise has an effect on LH and T secretion that is similar to that of fasting. And finally, the below sea level environmental factors, such as the high barometric pressure, as well as the genetic background of the athletes affect the pituitary and adrenal cortex as well as testicular tissue, resulting in the secretion of more LH and T.

Allopurinol enhances adenine nucleotide levels and improves myocardial function in isolated hypoxic rat heart.

Allopurinol, a competitive inhibitor of xanthine oxidase, was found to have a protective effect on ischemic myocardium. Its mechanism of action is still controversial. We used Langendorff isolated rat heart preparation to test the hypothesis that allopurinol could maintain a level of the adenine nucleotide pool (ATP, ADP, and AMP) that would protect and improve the functional activity of the heart during a period of hypoxia. Hearts were initially perfused for 30 min until steady state was attained. This was followed by 20 min of experimental perfusion divided into 5 min of control perfusion followed by 15 min of hypoxic perfusion with or without allopurinol in the perfusate. Hearts were quick-frozen and enzymatically analyzed for adenine nucleotides and creatine phosphate at the end of the hypoxic period. Left ventricular pressure, heart rate, and coronary flow were measured in all preparations. Allopurinol (0.1 mM) treated hearts had greater levels of ATP (12.3 +/- 0.8 vs. 9.3 +/- 0.8 micromol/g dry weight; p < 0.01). This improvement occurred in the presence as well as the absence of glucose. Total adenine nucleotides improved from 17 +/- 1 to 20.3 +/- 2.4 micromol/g dry weight (p < 0.01). This improvement also occurred in the presence as well as in the absence of glucose in the perfusate. It also improved cell energy state significantly in the presence as well as the absence of glucose. There was insignificant change in creatine phosphate. Allopurinol improved left ventricular pressure from 38 +/- 7% to 55 +/- 9% (p < 0.002) in the presence of glucose and from 8 +/- 3% to 27 +/- 6.3% (p < 0.001) in the absence of glucose. Coronary flow improved from 110 +/- 5% to 120 +/- 8% (p < 0.04) in the presence of glucose. These results support the suggestion that allopurinol at 0.1 mM exerts its protective effect on rat heart during hypoxia by enhancing the adenine nucleotide pool.

Lactate dehydrogenase activity and insulin and lactate levels at an altitude below sea level (-350 m) compared to those at an altitude above sea level (620 m) after exercise.

This study was designed to investigate the effect of exercise at 350 m below sea level altitude (-350 m) on the serum levels of lactate dehydrogenase (LDH), insulin, and lactate. The study was carried out on ten trained adult males with mean age of 23.3 +/- 3.4 years following a 21-km noncompetitive run. Venous blood was withdrawn from the subjects before exercise and 5 min post exercise. For comparison purposes, a similar study was performed with the same subjects but at 620 m above sea level (+620 m). The results show a significant increase in LDH and lactate levels after exercise only at low altitude (-350 m). Serum insulin levels decreased significantly after exercise at both altitudes. These changes in serum levels of LDH, insulin, and lactate at different altitudes suggest that a type of metabolic adjustment is present that meets energy requirements during exercise.

Seasonal pattern of leutinizing, follicle-stimulating hormone, testosterone and progesterone in adult population of both sexes in the Jordan Valley.

Differences were observed in hormonal levels between in both sexes of people living in Irbid City (620 meters above sea level) and in the Jordan Valley (360 meters below sea level). In addition, exercise was shown to differentially affect hormonal levels of both sexes at the above and below sea level locations. Serum levels of leutinizing hormone (LH) and testosterone (T) in adult male and serum levels of follicle-stimulating hormone (FSH) and progesterone (P) in adult female people were investigated in Irbid City and in the Jordan Valley during the years 1997 and 1998. The levels of these hormones were followed each month during this period. In males living in Irbid City, LH and T peaked from March through June, and in females at the same site, FSH and P also peaked from March through June. These data confirm the seasonal variation in sex hormones reported elsewhere in (wo)man and in other species. In males and females of the Jordan Valley, serum levels of LH, FSH, T and P were all higher than those of Irbid City throughout the year. Additionally, peaks of LH and T in male and FSH and P in female subjects in the Jordan Valley were observed from March through September. The high levels of these hormones and the extension of their peaks are suggested to be due to effects of the environmental factors of the Jordan Valley (high temperature, high barometric pressure) compared to those in Irbid City and other areas located at above sea level altitude.

Degradation of geosmin-like compounds by selected species of gram-positive bacteria.

Biodegradation of geosmin produced by Streptomyces halstedii (A-1 strain) was investigated using seven Gram-positive bacteria. Bacterial action on the A-1 extract was followed at 15, 45 and 120 min. Bacillus cereus ssp. thuringiensis HD-1, B. cereus 3711 and B. cereus ssp. mycoides 4379 showed no effect. However, Arthrobacter atrocyaneus, Arth. globiformis, Chlorophenolicus N-1053 and Rhodococcus maris caused a colour change from blue to yellow (positive reaction). These data suggest that geosmin can be degraded by specific species of Gram-positive bacteria. Biodegradation of geosmin, which causes bad odour in drinking water, can be used as a new technology in water treatment.

Exercise at low altitude (Jordan Valley) causes changes in serum levels of ACTH, insulin, cortisol and lactate.

This study was designed to examine the effects of exercise on adrenocorticotropic hormone (ACTH) and cortisol at low altitude (350 meters below sea level) and to compare these effects with those at a moderate level altitude (620 meters above sea level). Ten male trained athletes participated in a 21-K(m) non-competitive race. Serum levels of ACTH, luteinizing hormone (LH), growth hormone and cortisol were measured before and after the race at each of the altitudes. A significant increase in serum levels of ACTH was observed in response to this exercise only at low altitude. Serum levels of growth hormone were increased at both altitudes. Those of LH were not affected. Serum cortisol levels were increased following exercise at both altitudes. It is proposed here that ACTH may play a role in acclimatization to exercise at low altitudes. The role of growth hormone and LH in this conditioning process seems to be insignificant. Additionally, serum levels of insulin and lactate were also measured in these experiments. Exercise caused a decrease in serum insulin levels at both altitudes. Serum levels of lactate were decreased only at low altitude. These changes of serum levels of insulin and lactate suggest a type of metabolic adjustment to meet energy requirements. Changes in energy metabolism can be correlated by changes in the ratio of insulin to serum cortisol levels and those of other counter-regulatory hormones in response to exercise at both altitudes.

Acute effects of exercise at low altitude (350 meters below sea level) on hormones of the anterior pituitary & cortisol in athletes.

The purpose of this study was to examine the effects of exercise on anterior pituitary hormones (adrenocorticotropic hormone (ACTH), leutinizing hormone (LH) and growth hormone) as well as on cortisol at low altitude (350 meters below the sea level) and to compare these effects with those at a moderate level altitude (620 meters above the sea level). Ten male athletes with running experience participated in a 21-Km competitive race. Serum levels of ACTH, LH, growth hormone and cortisol were measured before and after the race at each of the altitudes. A significant increase in the serum levels of ACTH and growth hormone were observed in response to this exercise at low altitude. Similar exercise at 620 meters above the sea level resulted in a significant increase only in the serum levels of growth hormone. Serum levels of LH were not affected by this kind of exercise at both altitudes. Serum cortisol levels were increased following exercise at both altitudes. Altogether, these observations show a differential response of the anterior pituitary to exercise at low and normal altitudes. These data suggest that ACTH may have a role in the acclimatization to exercise at low altitudes. The role of growth hormone and LH in this conditioning process seems to be insignificant. The changes in serum cortisol levels in response to exercise at both altitudes correlate well with the effect of exercise on energy metabolism.

Cytochrome c oxidase in rat adrenal and liver: effects of anti-androgen treatment and studies in testicular feminized rats.

The role of androgen receptors in androgen-induced changes in rat adrenocortical and liver cytochrome c oxidase (COX) has been investigated. The anti-androgen flutamide, blunted the increase in COX activity and COX subunits II/III and IV, that is seen with androgen treatment. Testicular feminized (Tfm) rats had levels of COX activity and COX subunits II/II and IV in adrenal cortex and liver that were intermediate between the high levels found in normal male rats and the lower levels of normal female rats. These data suggest that androgen effects on adrenal and liver COX are mediated through interactions with androgen receptors known to be present in these issues. However, the observed changes in COX activity and COX subunits were not accompanied by altered levels of mRNAs encoding for COX II or COX IV.

Sex differences in cytochromes oxidase and P-45011 beta in the rat adrenal cortex.

A comparative study of cytochrome c oxidase (COX) activity and expression as well as cytochrome P-45011 beta expression has been carried out on the adrenal cortex of male and female rats. COX has also been examined in rat liver. In addition, the effect of testosterone replacement in orchiectomized male rats on adrenal COX has also been investigated. Adult male rats had higher COX activity in adrenal (255%) and liver (144%) mitochondria compared to adult female rats. Male rat adrenals and liver also had increased levels of COX II, a mitochondria-encoded COX subunit, and of COX IV, a nucleus-encoded COX subunit, as measured by Western analysis. In contrast, cytochrome P-45011 beta levels were lower (48%) in adrenal mitochondria from male rats than those of female rats. There was no significant sex difference in the level COX II and COX IV mRNAs in adrenal or liver, whereas the cytochrome P-45011 beta mRNA was 4-fold higher in female adrenals than in males. In male rats, orchiectomy caused a 23% decrease and testosterone replacement a 66% increase in adrenal COX activity. There were no corresponding changes in the levels of mRNAs encoding for COX subunits, suggesting post-transcriptional effects of testosterone on COX. These results are consistent with a regulatory role of testosterone on the expression of components of the respiratory and steroidogenic electron transport chains.

Sex differences in the steroidogenic and respiratory electron transport chains in the rat adrenal cortex.

Both steroid 11 beta-hydroxylation and cholesterol side chain cleavage occur in the mitochondria of adrenocortical cells and they require reducing power in the form of NADPH. There are direct sources of NADPH in rat adrenal mitochondria but another potential source of NADPH is the energy-linked transhydrogenase reaction. This suggests that there is a relationship between the steroidogenic and respiratory chains. We have elaborated upon this relationship by exploring the expression of cytochrome c oxidase (CO) and cytochrome P-45011 beta. We have studied the regulation of one mitochondrial-encoded (COII) and one nuclear-encoded (COIV) subunit. Normal, untreated male rats had higher basal levels of activity of CO in adrenal (255%) and liver (144%) mitochondria, compared to normal, untreated female rats. They also had increased COII (300% and 138%) and COIV (300% and 135%). Cytochrome P-45011 beta levels, however, were lower (48%) in adrenal mitochondria of male rats than those of female rats. Androgen treatment of male rats caused an increase in the activity of CO in the mitochondria of the adrenal gland with the levels being 171% of the corresponding controls. This increase in activity paralleled an increase in the levels of COII and COIV in the adrenal as measured by Western analysis. In contrast, adrenal cytochrome P-45011 beta levels were lower (68%). Androgen treatment caused no significant change in the levels of mRNA's for COII and COIV whereas cytochrome P-45011 beta mRNA was significantly lower than normal.(ABSTRACT TRUNCATED AT 250 WORDS)