Decreased thermal conductance during the luteal phase of the menstrual cycle in women

1990 ◽  
Vol 69 (6) ◽  
pp. 2029-2033 ◽  
Author(s):  
P. Frascarolo ◽  
Y. Schutz ◽  
E. Jequier

To study the influence of the menstrual cycle on whole body thermal balance and on thermoregulatory mechanisms, metabolic heat production (M) was measured by indirect calorimetry and total heat losses (H) were measured by direct calorimetry in nine women during the follicular (F) and the luteal (L) phases of the menstrual cycle. The subjects were studied while exposed for 90 min to neutral environmental conditions (ambient temperature 28 degrees C, relative humidity 40%) in a direct calorimeter. The values of M and H were not modified by the phase of the menstrual cycle. Furthermore, in both phases the subjects were in thermal equilibrium because M was similar to H (69.7 +/- 1.8 and 72.1 +/- 1.8 W in F and 70.4 +/- 1.9 and 71.4 +/- 1.7 W in L phases, respectively). Tympanic temperature (Tty) was 0.24 +/- 0.07 degrees C higher in the L than in the F phase (P less than 0.05), whereas mean skin temperature (Tsk) was unchanged. Calculated skin thermal conductance (Ksk) was lower in the L (17.9 +/- 0.6 W.m-2.degrees C-1) than in the F phase (20.1 +/- 1.1 W.m-2.degrees C-1; P less than 0.05). Calculated skin blood flow (Fsk) was also lower in the L (0.101 +/- 0.008 l.min-1.m-2) than in the F phase (0.131 +/- 0.015 l.min-1.m-2; P less than 0.05). Differences in Tty, Ksk, and Fsk were not correlated with changes in plasma progesterone concentration. It is concluded that, during the L phase, a decreased thermal conductance in women exposed to a neutral environment allows the maintenance of a higher internal temperature.

1997 ◽  
Vol 93 (1) ◽  
pp. 29-34 ◽  
Author(s):  
G. I. Adebayo ◽  
L. Hemeryck ◽  
M. Hall ◽  
D. Gasparro ◽  
M. Sinnott ◽  
...  

1. We undertook a temporal study of external sodium-stimulated lithium efflux (sodium—lithium countertransport) in erythrocytes and blood pressure by measuring these two parameters in three phases of the menstrual cycle (menstrual, midcycle and luteal phases) in 22 healthy, non-medicated females with regular menstrual cycles. Plasma oestradiol and progesterone levels were also determined. 2. Sodium—lithium countertransport activity (activity in 140 mmol/1 external NaCl) in the midcycle phase (0.176 ± 0.017 mmol h−1 l−1 of cells) was lower than in the menstrual (0.192 ± 0.016 mmol h−1 l−1 of cells, P < 0.030) and luteal (0.203 ± 0.018 mmol h−1 l−1 of cells, P < 0.030) phases. The Vmax of the transporter changed similarly but the Km was unaltered. 3. The plasma oestradiol level was 628.9 ± 39.1 pmol/1 in the midcycle phase, higher than in the menstrual (232 ± 18.5 pmol/1, P < 0.001) and luteal (372.5 ± 28.1 pmol/1, P < 0.001) phases. The progesterone level was 28.6 ± 2.1 nmol/1 in the luteal phase, and values were lower in the menstrual (2.5 ± 0.3 nmol/1, P < 0.001) and midcycle (2.8 ± 0.4 nmol/1, P < 0.001) phases. 4. There was no correlation between plasma oestradiol and sodium—lithium countertransport activity or Vmax during the menstrual cycle, but plasma progesterone was positively correlated with sodium—lithium countertransport activity (r = 0.478, P < 0.025, n = 22) and Vmax (r = 0.551, P < 0.045, n = 14) in the luteal phase. 5. Systolic blood pressure did not change significantly during the menstrual cycle. However, the diastolic pressure showed variation similar to that in sodium—lithium countertransport activity/Vmax, its midcycle value of 66.6 ± 1.4 mmHg being lower than that in the luteal (71.6 ± 1.3 mmHg, P < 0.025) and menstrual (70.6 ± 1.4 mmHg, P < 0.025) phases. 6. We conclude that sodium—lithium countertransport activity exhibits catamenial variation. Therefore we suggest, given this observation, that blood sampling for the assessment of the state of activity of the transport system be standardized in relation to a phase of the menstrual cycle in future studies involving females.


1991 ◽  
Vol 71 (6) ◽  
pp. 2107-2113 ◽  
Author(s):  
O. Shido ◽  
S. Sakurada ◽  
M. Tanabe ◽  
T. Nagasaka

Eleven rats were kept at an ambient temperature of 33.5 degrees C (HC) for 4–5 consecutive days, 9 additional rats were subjected to 33.5 degrees C for approximately 5 h daily (HI) for the same period, and 12 controls (Cn) were kept at 24 degrees C. After the exposure, the rats were placed in a direct calorimeter, where the wall temperature was set at 24 degrees C, and subjected to direct internal heating (6.2 W.kg-1, 30 min) through an intraperitoneal electric heater. After the first heat load and when thermal equilibrium had been attained again, the rats were subjected to indirect external warming by raising the jacket water temperature surrounding the calorimeter from 24.0 to 38.8 degrees C in 90 min. Hypothalamic (Thy) and colonic temperatures (Tco), evaporative and nonevaporative heat loss, and metabolic heat production (M) before the acute heat loads did not differ among the groups. During heat loads, the latent times for the onsets of the rises in tail skin temperature and evaporation were significantly longer, and Thy and Tco at the start of increases in heat losses tended to be higher, in the HC than in the Cn. M significantly decreased in all groups, but the magnitude and duration of reduction in M were significantly greater in the HC than in the Cn. There were no differences between the thermoregulatory responses to heat loads of the HI and Cn. These results suggest that in HC the threshold core temperature for heat loss response and the upper critical temperature have already shifted to a higher level and that HC respond to heat stress more strongly with the reduction of M than Cn. Short-term intermittent heat exposure had little effect on the thermoregulatory mechanisms in rats.


1998 ◽  
Vol 116 (3) ◽  
pp. 1734-1737 ◽  
Author(s):  
Jorge Haddad Filho ◽  
Agnaldo Pereira Cedenho ◽  
Vilmon de Freitas

CONTEXT: Endometrial maturation, important in the diagnosis of infertile couples, has been evaluated since 1950 using the Noyes criteria. Nevertheless, there is no consensus regarding the most suitable period of the luteal phase for performing the biopsy. OBJETIVE: This study evaluated the correlation between the histological dating of two endometrial biopsies performed in the same menstrual cycle, on luteal phase days six and ten. DESIGN: Prospective study. SETTING: Human Reproduction Division of the Federal University of São Paulo, referral center. PATIENTS:Twenty-five women complaining of infertility had their menstrual cycles monitored by ultrasound and LH plasma levels, to obtain evidence of ovulation. PROCEDURES: Endometrial biopsies were performed on luteal phase days LH+6 and LH+10 (luteal phase day 1 = LH+1 = the day that follows LH peak). Dating was done according to morphometric criteria, in which an endometrium sample is considered out of phase if the minimum maturation delay is one day. On day LH+6, blood was drawn for plasma progesterone level determination. RESULTS: All patients had an ovulatory cycle (mean LH peak: 47.4 U/L; mean follicular diameter on LH peak day: 18.9 mm; mean endometrial thickness on LH peak day: 10.3 mm; mean plasma progesterone level on day LH+6: 14.4 ng/ml). 14 patients had both biopsies in phase; 5 patients had out of phase biopsies only on day LH+6; 3 had out of phase biopsies only on day LH+10 and 3 patients had out of phase biopsies on both days. McNemar's test showed no statistical difference between these data (p>33.36%). CONCLUSIONS: The correlation found between the endometrial datings suggests that biopsies performed on either of these two days are suitable for evaluation of endometrial maturation.


1972 ◽  
Vol 69 (4) ◽  
pp. 731-738 ◽  
Author(s):  
B. Runnebaum ◽  
W. Rieben ◽  
A.-M. Bierwirth-v. Münstermann ◽  
J. Zander

ABSTRACT Serial plasma progesterone determinations were performed by gas-liquid chromatography in healthy women during 24 hour periods during the luteal phase of the cycle and during pregnancy. In 10 women during the hyperthermic phase of the cycle and in 14 women during early pregnancy (week 8–18) no significant circadian variation in the peripheral plasma progesterone concentration was observed. During later pregnancy (week 20–41) in 15 women, a statistically significant rise in the plasma progesterone concentration, usually from 8.00 a.m. until between 4.00 and 8.00 p. m. followed by a decrease after 8.00 p. m. until between 4.00 and 8.00 a. m., was demonstrated. The data indicate a diurnal change in the peripheral plasma progesterone level during the last trimester of pregnancy.


1979 ◽  
Vol 91 (1) ◽  
pp. 49-58 ◽  
Author(s):  
N. Goncharov ◽  
A. V. Antonichev ◽  
V. M. Gorluschkin ◽  
L. Chachundocova ◽  
D. M. Robertson ◽  
...  

ABSTRACT The peripheral plasma levels of luteinizing hormone (LH) as measured by an in vitro bioassay method were determined in daily plasma samples collected throughout one menstrual cycle in 8 normally menstruating baboons (Papio hamadryas). In addition LH was measured in plasma at three hourly intervals throughout the day in the follicular, peri-ovulatory and luteal phases of the cycle in 7, 3 and 6 animals respectively. The plasma levels of progesterone and oestradiol were also determined in the same samples throughout the menstrual cycle and during the period of the midcycle LH surge. The circulating LH profile measured throughout the cycle was characterized by a sharp mid-cycle surge (completed within one day) which was followed by a series of LH surges of varying intensity during the luteal phase of the cycle. The initial surge was considered to be pre-ovulatory as indicated by its relationship to the peak of plasma oestradiol and to the first significant increase in the levels of plasma progesterone above values found earlier in the follicular phase. A circadian rhythm of LH was observed during the luteal phase of the cycle; a 3 fold rise in LH was noted during the hours 15.00 to 24.00. No differences were observed throughout the day in the follicular phase of the cycle. The LH profile in three animals studied during the mid-cycle LH surge showed pronounced circadian changes with a major peak at 24.00 h. Plasma progesterone levels during this period rose sharply to values normally found in the mid-luteal phase of the cycle. A comparison of plasma levels of biologically active LH during the menstrual cycle of the baboon with those found in normally menstruating women reveals that in the baboon the LH peak is of much shorter duration and the levels in the follicular and peri-menstrual phases are significantly lower than in the human.


1972 ◽  
Vol 71 (3) ◽  
pp. 519-529 ◽  
Author(s):  
Johan A. Sundsfjord ◽  
A. Aakvaag

ABSTRACT The relative importance of endogenous progesterone and oestrogens on the rise in plasma renin activity and urinary aldosterone excretion in the luteal phase of the menstrual cycle has been investigated in two groups of young women. One group (luteal group) had plasma progesterone levels of 7–19.5 ng/ml (mean 12.3; sem 1.3) in the second half of the cycle. The other group (luteal failure group) had plasma progesterone levels of 1.5–3.0 ng/ml, (mean 2.1; sem 0.16), on the corresponding days in the second half of the cycle. The plasma oestrogen levels and the oestriol excretion did not differ between the groups at any stage of the cycle. In the luteal group the normal increase in plasma progesterone and plasma oestrogens and in oestriol excretion was accompanied by a doubling in plasma renin activity and urinary aldosterone excretion, whereas the plasma renin substrate levels did not change significantly. In the luteal failure group, no significant increase was found in either plasma renin activity or in urinary aldosterone excretion, in spite of the unchanged plasma oestrogen levels and oestriol excretion. In this group too the plasma renin substrate levels showed no change from the first to the second half of the cycle. It is concluded that the rise in plasma renin activity, plasma angiotensin II concentration and urinary aldosterone excretion in the luteal phase of the normal menstrual cycle is caused by increased progesterone production.


1970 ◽  
Vol 2 ◽  
pp. 7-12 ◽  
Author(s):  
Sultana Rokeya Mannan ◽  
Noorzahan Begum ◽  
Shelina Begum ◽  
Sultana Ferdousi ◽  
Taskina Ali

The present study was carried out to observe the correlation of some lung function parameters with the endogenous plasma progesterone level during different phases of menstrual cycle. The study was conducted on 30 healthy young female volunteers with age range of 20-25 years in the department of Physiology of BSMMU, Dhaka, during July 2005- June 2006. All the subjects were studied in 3 phases of menstrual cycle for 2 consecutive cycles. FVC, FEV1 , FEV1/FVC% for assessing lung function and plasma Progesterone level during each phase of menstrual cycle were measured by a portable spirometer and by ELIZA method in auto analyzer respectively. Comparison of the values between different phases were done by paired ‘t' test considering menstrual phase data as baseline due to negligible amount of progesterone detected in this phase. Correlation of FVC , FEV1 and FEV1/FVC%with Progesterone level in each 3 phases were analyzed by Pearson's correlation- coefficient test. Plasma progesterone level was much higher during luteal phase compared to those of follicular phases of both cycles (24.54ng/ml vs1.41 ng/ml; 26.56 ng/ml vs. 1.48 ng/ml). Both FVC and FEV1 were significantly higher (p<0.001) during luteal phase than those of follicular phases in both the cycles. FVC, FEV1 and FEV1/FVC%were positively correlated with plasma progesterone level but these relationships had failed to show any statistical significance. Similar to others, this study also observed increased ventilation and high endogenous progesterone level during luteal phase. Therefore increased ventilation might be related to high progesterone level during luteal phase owing to increased inspiratory muscle endurance and bronchial relaxation effect. Key words: Plasma Progesterone; Forced Vital Capacity; Forced Expiratory Volume; Menstrual cycle. DOI:10.3329/jbsp.v2i0.976 J Bangladesh Soc Physiol. 2007 Dec;(2): 7-12.


1972 ◽  
Vol 69 (4) ◽  
pp. 739-746 ◽  
Author(s):  
B. Runnebaum ◽  
K. Holzmann ◽  
A.-M. Bierwirth-v. Münstermann ◽  
J. Zander

ABSTRACT The influence of intravenous HCG infusions lasting for 2 hours on the peripheral plasma progesterone concentrations was investigated in healthy women on day 5 during the hyperthermic phase of the menstrual cycle and during week 6–19 and 31–39 of pregnancy. During the luteal phase the peripheral plasma progesterone level can be increased, on an average, up to 70 % with 5000 IU and up to 250 % with 20 000 IU. The highest plasma progesterone concentrations were reached about 8 hours after the beginning of the HCG infusion. In some experiments significantly elevated progesterone concentrations were still observed 20 hours after starting the HCG infusion. The results of intravenous HCG stimulation experiments during early pregnancy (10 000–20 000 IU) and during late pregnancy (5000–20 000 IU) showed no marked changes in the peripheral plasma progesterone concentrations.


1980 ◽  
Vol 239 (3) ◽  
pp. R241-R247
Author(s):  
K. R. Holmes ◽  
W. S. Hunter

Seven Telazol (CI-744)-[Telazol is an experimental drug (Parke, Davis) composed of two ingredients in equal amounts by weight: tiletamine HCl, designated chemically as 2-(ethylamino)-2-(2-thienyl)cyclohexanone-HCl, and zolazepam HCl, designated as 4-(o-fluorophenyl)-6,8-dihydro-1,3,8-trimethylpyrazolo-3,4-e 1,4 diazepin-7(IH)-one monohydrochloride] anesthetized rhesus monkeys (Macaca mulatta) were exposed to ambient temperatures (Ta) of 15, 23, 29, 35, and 38 degrees C to evaluate the effect of this dissociative anesthetic agent on thermoregulation. Thermal equilibrium in both anesthetized and control animals at Ta 15 degrees C was through peripheral vasoconstriction and metabolic heat production (M); shivering increased M in the anesthetized group to 1.7 times the resting M of 41.4 W x m-2. Both groups at Ta 38 degrees C regulated body temperature by vasodilation and increased skin evaporative heat loss (Esk) due to sweating. Anesthetized animals increased Esk from 6.4 W x m-2 at Ta 29 degrees C to 32.5 W x m-2 at Ta 38 degrees C. Panting was not observed in either group. Effective tissue thermal conductance was lowest at Ta 15 and 23 degrees C (6.9 and 7.6 W x m2 x degrees C-1, respectively), and increased with Ta's above 23 degrees C (45.0 W x m-2 at Ta 38 degrees C). These results indicate that Telazol-anesthetized monkeys maintain thermal balance at ambient temperatures from 15 to 38 degrees C, and that Telazol induces little or no impairment of thermoregulation in rhesus monkeys.


1970 ◽  
Vol 3 (1) ◽  
pp. 6-9 ◽  
Author(s):  
Sultana Rokeya Mannan ◽  
Noorjahan Begum

The present study has been carried out to observe the correlation of endogenous serum progesterone level with PEFR during luteal and follicular phases of two consecutive menstrual cycles. This study was conducted on 30 healthy young female volunteers with age ranges of 20- 24 years in the Department of Physiology of Bangladesh Shikh Mujib Medical University (BSMMU), Dhaka during July, 2005 to June, 2006. Serum progesterone level and PEFR of all subjects during all three phases of menstrual cycles were measured by ELISA method and a portable Spirometer respectively. Plasma progesterone level is highest during luteal phase; which is about 24 fold higher than that at follicular phases. (24.54ng/ml vs 1.4ng/ml). PEFR was positively correlated with progesterone level, but statistically not significant and it was significantly higher during luteal phase than follicular phase. This result indicates that changes in the pulmonary function occurred during different phases of menstrual cycle and this is more marked during luteal phase. DOI: http://dx.doi.org/10.3329/akmmcj.v3i1.10105 AKMMCJ 2012; 3(1): 6-9


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