Muscle sympathetic activity (MSA) was recorded in the peroneal nerve during sleep in 14 sleep-deprived healthy subjects. Continuous noninvasive recordings of finger blood pressure were obtained in 7 subjects. In light sleep (stage 2 sleep) the number of sympathetic bursts/min decreased to 90 +/- 8% (mean +/- SEM) and total MSA (= burst/min x mean burst area) to 89 +/- 5% of the awake value (P less than 0.05, n = 14). In deep sleep (stage 3-4) total MSA decreased further, to 71 +/- 8% of the awake value (n = 5). There was no close correlation between variations of depth of sleep and variations of sympathetic activity but during continuously deepening sleep MSA decreased progressively with time. In stage 2 sleep, high amplitude K complexes were accompanied by short-lasting increases of sympathetic activity. Since these increases of MSA were not preceded by decreases of diastolic blood pressure, which is known to evoke increased sympathetic nerve traffic in muscle nerves, we suggest that K complex related increases of MSA are signs of arousal which elicit both cortical EEG phenomena and activation of cerebral sympathetic centres. During desynchronized (REM) sleep, total MSA increased to 124 +/- 12% of the value in awake state (n = 5). The increases occurred mainly in short irregular periods, often related to rapid eye movements and there was an inverse relationship between the duration of the desynchronized sleep and the increase of total MSA. Our findings are similar to the data obtained in animal experiments and may partly explain changes of blood pressure during synchronized and desynchronized sleep reported previously in man.

The aim of this study was to investigate the role of nitric oxide (NO) in ovulation and ovarian steroidogenesis by the use of NO synthase (NOS) inhibitors and an NO donor administrated to the luteinizing hormone (LH)-stimulated ex-vivo perfused pre-ovulatory rat ovary. The ovaries were stimulated with LH (0.2 microgram/ml) alone or in combination with the phosphodiesterase inhibitor IBMX (200 micromol/l). The presence of both endothelial NOS (eNOS) and inducible NOS (iNOS) in the perfused rat ovary were detected by immunoblotting and a clear increase in amount of iNOS protein was seen after LH+IBMX stimulation. The addition of a non-selective NOS inhibitor, N(G)-monomethyl-L-arginine (L-NMMA; 300 micromol/l), to the perfusate significantly decreased ovulation numbers (median = 4. 0, range = 1-14) as compared with LH + IBMX stimulated control (12.0, 6-17). In contrast, an inhibitor with relative selectivity towards iNOS, aminoguanidine bicarbonate (AG, 300 micromol/l and 1 mmol/l), did not change the ovulation rate (11.5, 6-18 and 11.0, 7-15 respectively). In perfusions with only LH, a lower ovulation rate was seen but with similar effects (0.0, 0-8 for L-NMMA; 7.5, 3-12 for control and 7.0, 1-15 for AG 300 micromol/l). The administration of an NO donor, spermine NONOate, resulted in similar ovulation numbers as in LH-stimulated controls. The NO inhibitors did not affect steroid concentrations in the perfusion media, while 100 micromol/l NONOate increased progesterone production.

The ovulatory process in the rat comprises a period of about 12-15 h, from the time of the preovulatory LH surge to follicular rupture and extrusion of the oocyte. Follicular rupture is most likely caused, at least in part, by decreased tensile strength at the follicular apex due to degradation of collagen fibres of the extracellular matrix. It has been debated whether changes in intrafollicular pressure occur during the ovulatory process and whether such changes facilitate rupture of the follicle. In the present study, rats were primed with equine chorionic gonadotrophin (eCG, 10 iu) followed by hCG (10 iu) 48 h later. The intrafollicular pressure in the preovulatory follicle was recorded during 1 h at distinct time phases of the ovulatory process by use of an active servo-null pressure system based on the proportionality between electrical resistance and pressure within the tip of an inserted micropipette. The basal intrafollicular pressure was 16.6 +/- 1.0 mm Hg at the preovulatory phase (48 h after eCG) and increased gradually throughout the ovulatory process to 21.4 +/- 2.4 mm Hg at 4-7 h after hCG (mid-ovulatory phase) and 23.9 +/- 1.9 mm Hg at 8-12 h after hCG (late ovulatory phase; significantly higher (P < 0.01) than the preovulatory phase). Short-term peaks of increased pressure, possibly representing contractility, were not detected in follicles of the preovulatory phase, but were seen in most follicles of the mid- and late ovulatory phases. The mean amplitude of the short-term pressure increases was 12.3 +/- 3.2 mm Hg and the increases occurred at intervals of 24.7 +/- 3.6 s. These short-term increments in intrafollicular pressure were still present after hysterectomy had been performed. The wall tension index was calculated by measuring the follicular size and estimating the thickness of the follicle wall. The index increased from 93.9 +/- 13.3 at the preovulatory phase to 207.3 +/- 47.7 (mid-ovulatory phase) and to significantly higher values at the late ovulatory phase (320.9 +/- 33.5). In conclusion, this study shows that there is an increase in intrafollicular pressure in the ovulating follicle of the rat ovary during the late stages of the ovulatory process, and that short-term increases in intrafollicular pressure occur during the late phase of the ovulatory process. These changes in pressure may be essential for follicular rupture to proceed normally.

The aim of the present study was to examine the roles of the angiotensin II receptor subtypes, AT 1 and AT 2 , in ovulation, and to evaluate the contribution of angiotensin II-mediated pathways in regulation of ovarian blood flow. The AT 1 -specific antagonist, losartan, was administered alone or in combination with the AT 2 -specific antagonist, PD123319, to preovulatory rat ovaries perfused in vitro. Losartan (100 mol l − 1 ) did not affect the number of ovulations, whereas the combination of losartan (100 mol l − 1 ) and PD123319 (10 mol l − 1 ) inhibited ovulation. The angiotensin II antagonists did not affect the ovarian production of oestradiol, progesterone, prostaglandin E 2 (PGE 2 ), PGF 2␣ or plasminogen activator activity. Ovarian nitric oxide production was inhibited by losartan. Ovarian blood flow was measured by laser Doppler flowmetry in vivo in preovulatory rat ovaries. Intrabursal injection of angiotensin II reduced ovarian blood flow of gonadotrophin-stimulated rats. Losartan had no effect on basal ovarian blood flow but completely blocked the angiotensin II-induced reduction. In contrast, treatment with PD123319 increased basal ovarian blood flow and failed to reverse the effect of exogenously administered angiotensin II, indicating that under physiological conditions, ovarian blood flow of the rat is negatively regulated by angiotensin II mainly through the action of AT 2 . Taken together, these results indicate that two different types of angiotensin II receptor facilitate ovulation by cooperative mechanisms and that they regulate ovarian blood flow in a different manner.

Twenty-five patients with major depressive disorder according to RDC were examined with computerized quantitative EEG before antidepressive treatment. Normal EEGs were found in 20 patients and slight abnormality in five cases. Relationships between various EEG variables and pretreatment accumulation rate of 14C-5-HT and 3H-NA in rat synaptosomes, incubated in patients' plasma, and 5-HT in whole blood were studied. Age and current treatment with benzodiazepines were taken into account. There was an inverse relationship between alpha-1 amplitude in all derivations and beta-2 amplitude in the parieto-occipital derivation on one hand and pretreatment 14C-5-HT synaptosomal accumulation rate on the other. This result indicates that low 14C-5-HT synaptosomal accumulation rate is related to increased EEG alertness. This EEG pattern is suggested to be associated with a serotonergic subgroup of depression. The relationships between the other biochemical variables and the EEG patterns did not show any consistent pattern.

The involvement of leukotriene (LT) B(4) in the ovulatory process of the rat was investigated by the use of a LTB(4)-receptor antagonist (ZK158252 = L-ANT) administered either intrabursally in vivo or to the in-vitro perfused ovary. The in-vivo experiments revealed inhibition of human chorionic gonadotrophin (HCG)-induced ovulation by 500 micromol/l L-ANT (median 5.5, 25-75% range 1.0-6.0) compared with controls (median 9.0, range 6.25-13.5). In vitro, ovulation was induced by LH (0.2 microg/ml) + 3-isobutyl-1-methylxanthine (IBMX; 0.2 mmol/l). The ovary was perfused either for 20 h, to study ovulation rate, or for 10 h to examine ovarian concentrations of the ovulatory mediators matrix metalloproteinase (MMP)-2 and MMP-9, plasminogen activator (PA), prostaglandin (PG)E(2) and PGF(2 alpha). Addition of LH+IBMX resulted in a marked stimulation of steroid release and ovulations occurred in all ovaries (median 11.0, range 10.0-14.0). The L-ANT inhibited ovulation in a dose-dependent way (median 10.0, range 8.0-13.0 at 1 micromol/l; median 6.0, range 3.5-10.0 at 10 micromol/l; median 2.0, range 0.75-5.75 at 100 micromol/l). The intra-ovarian activity of PA was increased 1.5-fold by L-ANT (100 micromol/l), but the concentrations of PGE(2) and PGF(2 alpha) remained unaltered. While no changes in MMP-9 were observed, conversion from pro-MMP-2 to active MMP-2 was inhibited by L-ANT. These results suggest that activation of the LTB(4)-receptor within the ovary is involved in the ovulatory process and that the effects of LTB(4)-receptor activation are partly mediated via MMP-2.

did not ovulate and showed low secretion of progesterone and oestradiol. Addition of LH + 3-isobutyl-1-methylxanthine resulted in a marked stimulation of steroid release, and ovulations occurred in all ovaries (9.0 \ m=+-\ 0.9; mean \ m=+-\ sem). The protein tyrosine kinase inhibitors, genistein and tyrphostin A25, significantly inhibited ovulation at the higher concentrations tested (3.0 \m=+-\0.3at 100 \g=m\molgenistein l \m=-\1; 5.8 \ m=+-\ 1.0 at 500 \g=m\mol tyrphostin A25 l \ m=-\ 1) but no effect was seen at lower concentrations. The presence of genistein and tyrphostin A25 at any concentration used did not significantly decrease the LH + 3-isobutyl-1-methylxanthine-induced progesterone or oestradiol concentrations. The intraovarian concentrations of plasminogen activator activity, and prostaglandin E2 and F2\ g=a\ were not altered by the presence genistein (100 \g=m\moll \ m=-\ 1) . In conclusion, the results of the present study indicate that protein tyrosine kinase signalling pathways are integral parts of the mammalian ovulatory process but do not involve actions on the synthesis of steroids, plasminogen activator or prostaglandins.

The matrix metalloproteinases (MMPs) play critical roles in the ovulatory process. Their expression and activity, together with those of the endogenous tissue inhibitors of metalloproteinases (TIMPs), are stimulated by LH. The LH surge initiates a cascade of events resulting in ovulation and formation of the corpus luteum via activation of protein kinases A and C, as well as tyrosine kinases. In vitro perfused rat ovaries were untreated, or treated with LH (0.2 microg ml(-1)) plus 0.2 mmol 3-isobutyl-1-methylxanthine l(-1) with 0, 10 or 100 micromol genistein l(-1) (an inhibitor of tyrosine kinases) to assess whether tyrosine kinases are mediators of the LH-stimulated increase in ovarian expression of the MMPs and TIMPs. After 10 h of perfusion, ovaries were collected and frozen until RNA isolation. Northern and RNase protection analyses were used to measure mRNA encoding collagenase 3, gelatinases A and B, and TIMPs-1, -2 and -3. Treatment with LH plus 3-isobutyl-1-methylxanthine resulted in a two- and fivefold increase in mRNA encoding collagenase 3 and TIMP-1, respectively (P < 0.05). Treatment with 100 micromol genistein l(-1) blocked the LH-stimulated increase in collagenase 3 (0.012 +/- 0.002 versus 0.028 +/- 0.005 relative units for 100 micromol genistein l(-1) versus LH; P < 0.05), whereas neither dose of genistein affected LH-induced TIMP-1 expression. LH alone or with genistein did not alter the expression of mRNA encoding TIMP-2 and TIMP-3, or mRNA encoding gelatinases A and B. These data indicate that tyrosine kinases play a role in the LH-induced tissue remodelling required for ovulation by mediating the LH-stimulated expression of collagenase 3.