Plasma renin activity, active and inactive renin concentrations, and their responses to beta 1-adrenoceptor blockade with metoprolol in hyperthyroidism

Plasma renin activity (PRA), plasma renin concentration (PRC), inactive renin concentration (IRC) and total renin concentration (TRC) were measured in 31 normal controls and in 8 patients with hyperthyroidism. TRC was determined as angiotensin I generated with sheep renin substrate after an acid activation of plasma. The angiotensin I of non-acidified plasma was expressed as PRC. IRC was calculated as TRC minus PRC. The mean values for PRA, PRC, IRC and TRC were significantly (P less than 0.05 to P less than 0.01) higher in the hyperthyroid patients than in the normal or euthyroid controls. The administration of a beta 1-adrenergic blocker, metoprolol (120 mg/day for 14 days), produced a significant (P less than 0.05 to P less than 0.01) fall in levels of T4, PRA and TRC, and reduced the active renin ratio calculated from PRC/TRC significantly (P less than 0.025), as compared to the pretreatment values. Our observations support the idea that the higher PRA in hyperthyroidism is due to an increased secretion of renin. Furthermore, the results may indicate that the conversion of inactive to active renin is accelerated in hyperthyroidism, possibly by an increased sympathetic activity.     

Efficacy of intermittent, regional microclimate cooling.

The vasomotor response to cold may compromise the capacity for microclimate cooling (MCC) to reduce thermoregulatory strain. This study examined the hypothesis that intermittent, regional MCC (IRC) would abate this response and improve heat loss when compared with constant MCC (CC) during exercise heat stress. In addition, the relative effectiveness of four different IRC regimens was compared. Five heat-acclimated men attempted six experimental trials of treadmill walking ( approximately 225 W/m(2)) in a warm climate (dry bulb temperature = 30 degrees C, dewpoint temperature = 11 degrees C) while wearing chemical protective clothing (insulation = 2.1; moisture permeability = 0.32) with a water-perfused (21 degrees C) cooling undergarment. The six trials conducted were CC (continuous perfusion) of 72% body surface area (BSA), two IRC regimens cooling 36% BSA by using 2:2 (IRC(1)) or 4:4 (IRC(2)) min on-off perfusion ratios, two IRC regimens cooling 18% BSA by using 1:3 (IRC(3)) or 2:6 (IRC(4)) min on-off perfusion ratios, and a no cooling (NC) control. Compared with NC, CC significantly reduced changes in rectal temperature ( approximately 1.2 degrees C) and heart rate ( approximately 60 beats/min) (P < 0.05). The four IRC regimens all provided a similar reduction in exercise heat strain and were 164-215% more efficient than CC because of greater heat flux over a smaller BSA. These findings indicate that the IRC approach to MCC is a more efficient means of cooling when compared with CC paradigms and can improve MCC capacity by reducing power requirements.     

Diagnosis of pregnancy in wood bison using a bovine assay for pregnancy-specific protein B

Blood samples were collected from 51 wood bison (Bison bison athabascae ) and evaluated for the presence of an antigen that cross-reacted with antisera to pregnancy-specific protein B(PSPB). The objective of this study was to determine if the PSPB radioimmunoassay (RIA) was a reliable indicator of pregnancy in these animals. Pregnancy of mature females was determined either at autopsy (20 animals) or by palpation per rectum after chemical immobilization (18 animals). The antigen was not detected in either males or juvenile females. There was minor cross-reaction in sera of one of nine nonpregnant females that had been exposed to males. The antigen was found in the sera of 25 of 27 females that were confirmed pregnant. It was concluded that the PSPB RIA was a useful tool in the determination of pregnancy in wood bison.     

Physical and activity changes associated with pregnancy in captive lowland gorillas (Gorilla gorilla gorilla)

The physical appearance and the behavior of five lowland gorilla females at two zoos were recorded before and during 14 pregnancies. Whereas only the quality of changes associated with pregnancy had been described previously, in this study the behavior of the females was recorded quantitatively and evaluated statistically. All females at Stuttgart showed distention of the abdomen three to four months before delivery and development of the breasts a few weeks before parturition. Milk was produced by the third month in one case, and in the sixth month or later in the others, sometimes after delivery. The female at Frankfurt stopped social play seven days after conception; the Stuttgart females, in general, stopped, in the first weeks of pregnancy. Social activity and locomotion decreased considerably within the first three months in all females and were significantly different between the pregnant and the nonpregnant state in all the Stuttgart females. In this study, as in others in the literature, behavioral changes were much more reliable signs of pregnancy than were physical changes. Thus the quantitative results confirm those obtained solely by qualitative observation.     

Content of NCAM, the neural cell adhesion molecule, in the brain of rats subjected to prenatal stress

The content of NCAM, the neural cell adhesion molecule, was studied in the cerebral cortex, hippocampus, striatum, cerebellum, and pons of 15- and 30-day-old rats, the offspring of intact females and females subjected to stress during pregnancy. At the 30th day of the postmatal development, opposite NCAM concentration changes were observed in the cortex and other brain parts of the offspring of stressed rats. These differences can be related to a deficiency of mature synapses in the forebrain of prenatally stressed rats and adaptation rearrangements in the neuronal systems of the brainstem and cerebellum.     

Sexual dimorphism,asymmetry, and the effect of reproduction on pelvis bone in the bank vole, <Emphasis Type="Italic">Myodes glareolus</Emphasis>

Sexual dimorphism in anatomical traits has been widely studied in animals. Although pelvis dimorphism was mostly studied in humans, it occurs also in many other mammalian species. Here, we investigated sexual dimorphism in the pelvis of the bank vole Myodes glareolus using individuals with known sex and reproductive status of females (parous vs nulliparous). The analyses revealed that the size and shape of pelvis differed significantly between sexes, as well as between nulliparous and parous females. In comparison with males, females had a significantly longer pelvis and pubis bones and a longer obturator foramen length, but a smaller pubis width. Interestingly, the difference between parous and nulliparous females resembles that between females and males: parous females had bigger pelvis, which probably resulted from changes during pregnancy and after birth. Left bones were on average larger than right ones, but the magnitude of directional asymmetry was not different between sex and reproduction group. Moreover, we noticed that fluctuating asymmetry of pelvis and pubis length was higher in females than in males and higher in parous than in nulliparous females, what is presumably associated with locomotor performance. A discriminant function analysis performed for the four bone size traits showed that the traits can be effectively used for a nearly perfect recognition of sexes and also a quite reliable recognition of the reproductive status of females.     

Non-invasive repeated measurement of urinary progesterone, 17beta-estradiol, and testosterone in developing, cycling, pregnant, and postpartum female mice

Excretory samples from adult female mice were collected non-invasively during development, estrous cycling, pregnancy, and postpartum. In initial studies, urinary measures were statistically more dynamic over days than were fecal measures; thus subsequent studies focused on urine. Higher 17beta-estradiol levels were present in isolated females than in those exposed to males. In cycling females, urinary 17beta-estradiol was more variable than were measures of testosterone or progesterone, showing peaks with an approximate 5-day periodicity. When urinary estradiol and progesterone were monitored in conjunction with vaginal smear cell counts, patterns were idiosyncratic; most females showed distinct peaks in urinary steroids, not in clear synchrony with vaginal cell cornification. Levels of progesterone rose markedly during the first 10 days of pregnancy, then declined before birth. Estradiol showed a substantial peak on days 7-8 of gestation in all females measured. Urinary testosterone was not dynamic during pregnancy, but rose in immediate prenatal and postpartum measures. During post-weaning, pre-pubertal development, urinary levels of progesterone remained constant but levels of estradiol rose substantially over time.     

Effect of exposure of pregnant rats to cadmium on prenatal and postnatal development of the young

Cadmium chloride in doses of 2, 12 and 40 mg Cd/kg was administered per os to pregnant rats from the 7th to 16th day of pregnancy. In another experiment female rats were exposed to cadmium oxide at a concentration of 0.02 mg Cd/m3 or 0.16 mg Cd/m3 for 5 hours a day and 5 days weekly for a period of 5 months or 1 mg Cd/m3 for 4 months. The exposure was then continued during mating and from the 1st to 20th day of pregnancy. A decrease in fertility was only observed in females exposed by inhalation to cadmium oxide at a concentration of 1 mg Cd/m3, at which concentration cadmium exhibits a considerable toxic effect on the whole organism. The young of females orally treated with CdCl2 in a dose of 40 mg Cd/kg displayed congenital defects in the form of sirenomelia or amelia, as well as raised cadmium levels in tissues. A retardation of intrauterine development manifested by lower body weight and slowed down osteogenesis was observed in the other groups. A cadmium concentration increase was not found in the tissues of the young in these groups. Inhalation exposure to 0.16 mg Cd/m3 of females prior to and during pregnancy induced in their young a decrease in viability, lower body weight gain, prolongation of latency in the negative-geotaxis test, lower locomotor activity and deteriorated development of the conditioned-reflex response. The offspring of females exposed to 0.02 mg Cd/m3 displayed lowered locomotor activity and worsened consolidation of the conditioned-reflex response.     

Expression of adult female patterns of sexual behavior by male, female, and pseudohermaphroditic female rhesus monkeys

Gonadally intact pseudohermaphroditic female and normal female and neonatally castrated male rhesus monkeys were given estrogen treatment as adults and evaluated for attractivity, proceptivity, and receptivity during tests with a tethered stud male. Pseudohermaphrodites were produced by injecting their mothers during pregnancy with either testosterone propionate (TP) or dihydrotestosterone propionate (DHTP). Castrated males had reliably lower attractivity than normal females on all indicator responses shown by the tethered males. Additionally, castrated males showed reliably fewer proceptive responses on 4 of 5 measures than normal females. Receptivity could not be assessed in this situation for castrated males, because tethered males never contacted them unless the castrated males were displaying presentation. No reliable differences were observed between pseudohermaphrodites produced by prenatal treatments with TP or DHTP. Pseudohermaphrodites generally showed reliably less attractivity and proceptivity than normal females and reliably more of these traits than castrated males. Attractivity scores for pseudohermaphrodites were not different from those for normal females until proximity to the tethered male was established. Receptivity was not different in pseudohermaphrodites compared with normal females. Results indicate prenatal androgenization and its developmental sequelae lead to a defeminization in adulthood which, in this testing situation, was principally manifested by a deficiency in the performance of proceptive behaviors. Additionally, defeminization in rhesus monkeys, unlike that demonstrated in rodents, does not depend upon actions of an aromatizable androgen.     

Relaxin as a diagnostic tool for pregnancy in the coyote (Canis latrans)

The diagnosis of pregnancy in the domestic dog (Canis familiaris) often employs specialized equipment, experienced staff, and the cooperation of the bitch. These procedures can be challenging when the subject is a wild canid, particularly in a field setting. In addition, reproductive hormone assays are unreliable as a diagnostic tool because the estrous profiles of pregnant and pseudopregnant canines are similar. However, research has demonstrated that the hormone relaxin can be detected in maternal blood after embryonic implantation, but remains negligible in non-pregnant females. We investigated the use of relaxin as a diagnostic marker of pregnancy in the coyote (C. latrans). A commercially available canine relaxin enzyme immunoassay (ReproCHEK) was used to test plasma collected from 124 female coyotes over four consecutive breeding seasons. Mating activities of the captive females were observed; then peripheral blood samples were collected at intervals throughout pregnancy, as well as after parturition. Results demonstrated that relaxin could be detected in the plasma of pregnant coyotes after 28 days of gestation, and in some cases as early as 23 days, while non-pregnant females and male coyotes consistently tested negative. Relaxin also remained detectable in the plasma of the majority of females tested 10-12 weeks after parturition. This qualitative assay for relaxin proved to be a reliable diagnostic tool for pregnancy in the coyote. In addition, blood sampling was relatively easy, could be accomplished with minimal handling, and did not require sedation or anesthesia.     

Clitoral stimulation and the effect of age, breed, technician, and postpartum interval on pregnancy rate to artificial insemination in beef cattle

An experiment was conducted to assess the effect of clitoral stimulation on pregnancy rate to artificial insemination in 1,856 beef females. For unadjusted data, pregnancy rate to first service in nonstimulated females was 61% for cows and 59% for heifers, and that of females receiving clitoral stimulation was 69% for cows and 58% for heifers. After adjusting the data for the influences of age, breed, technician, and postpartum interval, clitoral stimulation increased first service pregnancy rate in cows (74 +/- 3% vs 59 +/- 3%, P<0.05), but not in heifers (53 +/- 5% vs 57 +/- 5%, P>0.10). Postpartum interval significantly influenced pregnancy rate, regardless of treatment, and clitoral stimulation was beneficial when applied to cows with relatively short postpartum intervals. Variation in the effect of clitoral stimulation on pregnancy rate was observed among technicians. Clitoral stimulation improved pregnancy rate more effectively in 3 to 4 year old cows than in cows 2 years old and cows 5 years of age or older. We concluded that clitoral stimulation at the time of artificial insemination was an effective means of increasing pregnancy rate in cows, but not in heifers.     

Alpha fetoprotein levels in newborn infants with reference to sex, gestational age and birth weight

Alpha fetoprotein (AFP) concentration was higher in the mature full term male infants than age matched females. An inverse correlation, at birth, between cord serum AFP level and duration of pregnancy was observed. In contrast no correlation between body weight and AFP levels exists in babies of either sex at identical gestational age.     

Influence of pre- and post-copulatory pair contact on pregnancy success in Djungarian hamsters, Phodopus campbelli

Females housed with their mates for 3 or 4 days before mating took place (i.e. early in the oestrous cycle at the time of introduction to the mate) were significantly more likely to litter than were females housed with their mates for only 1 or 2 days before mating. The duration of post-copulatory pair contact had a complex effect on pregnancy success. While only 41% of females littered when they had 24 h of post-copulatory pair contact, females exposed to either longer or shorter durations of post-copulatory pair contact littered at significantly higher rates. Exposure to a strange male 24-48 h after mating did not produce a strange-male induced pregnancy block. The critical parameter responsible for the decrease in the number of females littering was the absence of the mate, irrespective of the presence or absence of a strange male. If this pattern of pregnancy block is adaptive for females, it seems probable that females in the wild require substantial levels of paternal investment by their mates.     

Endocrinology of pregnancy and early pregnancy detection by reproductive hormones in reindeer (Rangifer tarandus tarandus)

The endocrinology was studied throughout pregnancy in reindeer (Rangifer tarandus tarandus) located in Oulu, Finland (65 degrees N, 25 degrees E) with 13 captive, semi domestic adult females. Blood samples were analyzed for plasma progesterone (P4), estradiol (E2) and estrone sulphate (E1SO4), 15-ketodihydro-PGF2alpha (PG-metabolite) and pregnancy associated glycoproteins (PAG). The mean plasma P4 concentration peaked twice during gestation: at around 24 and three weeks prior to calving. In pregnant females the plasma PAG concentration increased over basal concentrations 21-30 days after the estimated day of conception and peaked at the time of calving. The concentrations of E2 and E1SO4 remained low until 60 days before calving when a rapid increase was found for both hormones. The mean plasma concentration of PG-metabolite increased throughout pregnancy to a maximum at parturition. The estimated mean (range) gestation length was 216 (212-220) days. Judged from measures on reproductive organs collected from 86 free-ranging, semi-domestic female reindeer of unknown age presented for slaughter at Roros, Norway (63 degrees N, 11 degrees E) in the second week of December 1999, it was concluded that the breeding season lasted from early September until the end of November. The results also showed that plasma PAG concentration could provide a tool for detection of pregnancy in reindeer.     

Reproductive performance of a laboratory colony of the deermouse, Peromyscus maniculatus gambelii.

During a 23-mo period approximately 600 litters and 2,500 offspring were produced in a laboratory colony established with wild-trapped deermice (Peromyscus maniculatus gambelii). The incidence of pregnancy and size of litters increased with domestication. Average litter size was 4.3 for all litters and 4.1 and 4.7 for litters born to wild-trapped and first generation females, respectively. Litter size increased up to the seventh sequential pregnancy for both wild-caught and first-generation females and then tapered off. In all litters more males were born than females. The departure from a 1:1 ratio was significant for the combined data and for litters of first-generation females, but not for litters of wild-caught females.     

小熊猫妊娠期粪便中孕酮、雌二醇的水平变化

2000年3—8月在成都动物园和成都大熊猫繁育研究基地,用放射免疫分析法测定了6只雌性小熊猫粪样中孕酮（P）和雌二醇（E2）的水平变化,同时对其繁殖行为进行了观察。研究结果表明,交配后的雌体粪样中E2浓度下降至基础水平,P浓度在30d后上升至150ng／g以上;怀孕雌体在妊娠期粪样中P水平在200ng／g以上,P峰值可以达500ng／g以上;假妊娠者粪样中P水平一般不超过150ng／g,P峰值在200ng／g以下;雌体产前半个月孕酮迅速下降,E2缓慢上升,产后P保持在基础水平。这意味着可通过测定粪便中P水平进行早孕诊断、产期预测和真假妊娠判断。根据行为观察和粪样激素分析可知,雌兽妊娠期为123—128d（X=124,N=5）,产仔率为1．8／胎（N=5）。     

DETERMINATION OF PREGNANCY STATUS FROM BLUBBER SAMPLES IN MINKE WHALES (BALAENOPTERA ACUTOROSTRATA)

Measurement of progesterone concentration in blubber was developed as a method to detect pregnancy in minke whales. Progesterone was extracted and quantified from blubber samples of minke whale carcasses by radioimmunoassay. Results showed a highly significant difference (almost 60-fold) between blubber progesterone concentrations of anatomically determined pregnant females versus non-pregnant female or male carcasses. The results of the study suggest that the blubber progesterone concentrations might be used to determine pregnancy status in free-ranging whales.     

Estimation of the fertility rates of Japanese wild boars (Sus scrofa leucomystax) using fetuses and corpora albicans

Effective population control of Japanese wild boar (Sus scrofa leucomystax) requires reliable information about population dynamics. Fertility rate is the fundamental component of reproduction to evaluate population dynamics. However, little is known regarding the fertility rate of Japanese wild boar. The traditional hunting practices make it difficult to obtain pregnant females and calculate the fertility rate by checking fetuses as is performed in other countries. Therefore, we focused on the corpora albicans (CA) as the CA remains in the ovaries of postpartum females after pregnancy. This study aimed to evaluate the utility of CA and estimate the fertility rate of Japanese wild boars using CA. Histological analysis of ovaries enabled us to discriminate type 1 CA, which remains for 1 year after breeding. Type 1 CA is a superior indicator compared with lactation in the non-pregnancy season because it allows verification of postpartum females over a long period. The fertility rate was calculated by the combination of pregnant and postpartum females using fetuses and type 1 CA from April to November. The fertility rate of the females captured after the second pregnancy season was 90.3 % during the pregnancy period and 100 % during the non-pregnancy period. The high fertility rate of adult females suggests that intensive adult female harvesting is needed. Our new method to determine fertility rates contributes to developing a monitoring system to adequately control Japanese wild boar population.     

Seasonality, sociality, and reproduction: Long-term stressors of ring-tailed lemurs (Lemur catta)

Fecal glucocorticoid (fGC) concentrations are reliable, non-invasive indices of physiological stress that provide insight into an animal's energetic and social demands. To better characterize the long-term stressors in adult members of a female-dominant, seasonally breeding species - the ring-tailed lemur (Lemur catta) - we first validated fecal samples against serum samples and then examined the relationship between fGC concentrations and seasonal, social, demographic, genetic, and reproductive variables. Between 1999 and 2006, we collected 1386 fecal samples from 32 adult, semi-free-ranging animals of both sexes. In males and non-pregnant, non-lactating females, fGC concentrations were significantly elevated during the breeding season, specifically during periods surrounding known conceptions. Moreover, group composition (e.g., multi-male versus one-male) significantly predicted the fGC concentrations of males and females in all reproductive states. In particular, the social instability introduced by intra-male competition likely created a stressor for all animals. We found no relationship, however, between fGC and the sex, age, or heterozygosity of animals. In reproducing females, fGC concentrations were significantly greater during lactation than during the pre-breeding period. During pregnancy, fGC concentrations were elevated in mid-ranking dams, relative to dominant or subordinate dams, and significantly greater during the third trimester than during the first or second trimesters. Thus, in the absence of nutritional stressors, social dominance was a relatively poor predictor of fGC in this female-dominant species. Instead, the animals were maximally challenged by their social circumstances and reproductive events—males by competition for mating opportunities and females by late-term gestation and lactation.     

Changing costs of reproduction: age-based differences in reproductive allocation and escape performance in a livebearing fish

The reproductive value hypothesis predicts that if residual reproductive value declines as a female ages, then young females should allocate less of available energy to current fecundity and more to future reproduction; whereas, older females should allocate more of available energy to current fecundity and less to future reproduction (i.e. survival). We test the prediction that older female Gambusia affinis exhibit higher levels of allocation to reproduction (i.e. fecundity) and consequently experience greater decline in escape performance (survival cost) during pregnancy compared to young females. Old females had relatively larger clutch wet masses and clutch wet mass increased more during pregnancy compared to young females. Correspondingly, old females exhibit a significant decline in escape velocity over the course of pregnancy; whereas young females show no change in escape velocity throughout pregnancy. Old females have higher escape velocities early in pregnancy and their performance only declines to about the level of performance of young females by the end of pregnancy. Thus, although old females exhibit a greater decline in performance they are better able to ameliorate the cost of decreased performance.