Effects of simulated increases in body weight from birth on the growth of limb bones in rats

The purpose of this study was to subject groups of newborn male and female Sprague-Dawley rats each to a specific 10% simulated increase in body weight, to a maximum of a doubling of body weight, to study the effects of quantified, increased, intermittent, compressive forces on limb bone growth. Chronic centrifugation was employed. After 90 days of centrifugation the rats were sacrificed. The humerus, radius, ulna, femur, and tibia were removed from each animal, cleared of all soft tissues, measured and weighed. Tukey's Studentized multiple range test was performed to identify aggregations (sets) of force groups between which there are significant differences. The data suggest that newborn male and female rats subjected to simulated increases in body weight, within the range used for this study, undergo enhanced general body growth and limb bone growth.     

Bone mineral content of limb bones of male weanling rats subjected to 30 and 60 days of simulated increases in body weight

The purpose of this study was to subject groups of male rats each to a specific 10% simulated increase in body weight, ranging from 1.1 to 2.0 g. Constant centrifugation was employed. After 30 and 60 days, rats were sacrificed and perfused with 10% BNF. The humerus, radius, ulna, femur, and tibia were removed, cleared of all soft tissues, weighed, decalcified with EDTA, and reweighed. Bone mineral content (BMC) was determined using the formula: [(Wu - Wd) divided by Wu] X 100. Tukey's multiple range test was used. The data suggest that male weanling rats subjected to simulated increases in body weight, within the range used in this study, undergo enhanced BMC, a bimodal curve describing the relationship between BMC and simulated increases in body weight.     

Effects of simulated increases in body weight on the growth of limb bones in hypophysectomized rats

The purpose of this study was to subject groups of hypophysectomized male and female rats each to a simulated specific 10% increase in body weight, to a maximum of a doubling of body weight, in order to study the effects of quantified, increased, intermittent, compressive forces on limb bone growth. Chronic centrifugation was employed. 21-day-old Sprague-Dawley rats were used. After 60 days of centrifugation, the rats were sacrificed. The humerus, radius, ulna, femur and tibia were removed from each animal, cleared of all soft tissues, and the bone lengths measured on Helios calipers with an accuracy of 1/20 mm. The data were corrected for differences due to individual body weight by dividing bone lengths by the cube root of the body weight of the same animal. Tukey's studentized multiple-range test was performed to identify aggregations (sets) of force groups between which there are significant differences. The data suggest that the simulated increases in body weight, within the range used for this study, enhance bone growth in hypophysectomized female and male rats similarly - hypophysectomy being a condition known to inhibit bone growth.     

The effect of administration of estradiol and testosterone on body growth of young male rats.

The influence of estradiol and testosterone on body growth of young male Wistar rats was investigated. In the first experiment, estradiol was given to intact ad libitum fed male rats at 32, 37 and 42 days of age. Moreover, two untreated groups of animals were used: one was fed restrictedly according to the food intake of animals receiving estradiol and another was fed ad libitum. The animals were sacrificed at 47 days of age. Both untreated groups of animals achieved significantly higher body weight and length of tibia than estradiol treated animals. Also the growth of the tail of untreated animals was more intensive than that of estradiol treated animals. In the second experiment, estradiol was given to intact ad libitum fed male rats at 30, 35 and 45 days of age. Moreover, testosterone was given to a half of these animals at 45, 50 and 55 days of age. The animals were sacrificed at 60 days of age. Administration of testosterone significantly increased the growth of the tail and tibia in comparison to the animals which did not receive testosterone after estradiol administration. The results of the present study show that the inhibitory effect of estradiol on body growth of young male rats is not only the result of decreased food intake and that testosterone can improve the skeletal growth of male rats altered by previously given estradiol.     

赤霉病麦中毒研究Ⅲ．赤霉病麦粗毒素的生殖毒理学研究

赤霉病麦粗毒素为赤霉病麦的乙醇提取物,其中脱氧雪腐镰刀菌烯醇和玉米赤霉烯酮含量分别为11100 ppm和605ppm。家猫和鸽子的致吐剂量分别为300和400 mg粗毒素/kg体重。成年雌雄大鼠经口LD_(50)分别为8150和10550mg粗毒素/kg体重。1000mg粗毒素/kg体重经口给予未成年雌性大鼠,未见有雌激素亢进反应。将粗毒素含量0.01,0.1和0.5％的饲料喂养断奶Wistar大鼠210—301天,在此期间大鼠繁殖F1a和F1b两代仔鼠,并观察至断奶。在所有剂量组均观察到对生长、发育或生殖的程度不同地损害。本文讨论了赤霉病麦对大鼠生殖力的影响及其作用机制。     

Dose- and time-dependent effects of a novel (−)-hydroxycitric acid extract on body weight,hepatic and testicular lipid peroxidation,DNA fragmentation and histopathological data over a period of 90 days

(–)-Hydroxycitric acid (HCA), a natural extract from the dried fruit rind of Garcinia cambogia (family Guttiferae), is a popular supplement for weight management. The dried fruit rind has been used for centuries as a condiment in Southeastern Asia to make food more filling and satisfying. A significant number of studies highlight the efficacy of Super CitriMax (HCA-SX, a novel 60% calcium-potassium salt of HCA derived from Garcinia cambogia) in weight management. These studies also demonstrate that HCA-SX promotes fat oxidation, inhibits ATP-citrate lyase (a building block for fat synthesis), and lowers the level of leptin in obese subjects. Acute oral, acute dermal, primary dermal irritation and primary eye irritation toxicity studies have demonstrated the safety of HCA-SX. However, no long-term safety of HCA-SX or any other (–)-hydroxycitric acid extract has been previously assessed. In this study, we have evaluated the dose- and time-dependent effects of HCA-SX in Sprague-Dawley rats on body weight, hepatic and testicular lipid peroxidation, DNA fragmentation, liver and testis weight, expressed as such and as a % of body weight and brain weight, and histopathological changes over a period of 90 days. The animals were treated with 0, 0.2, 2.0 and 5.0% HCA-SX as feed intake and the animals were sacrificed on 30, 60 or 90 days of treatment. The feed and water intake were assessed and correlated with the reduction in body weight. HCA-SX supplementation demonstrated a reduction in body weight in both male and female rats over a period of 90 days as compared to the corresponding control animals. An advancing age-induced marginal increase in hepatic lipid peroxidation was observed in both male and female rats as compared to the corresponding control animals. However, no such difference in hepatic DNA fragmentation and testicular lipid peroxidation and DNA fragmentation was observed. Furthermore, liver and testis weight, expressed as such and as a percentage of body weight and brain weight, at 30, 60 and 90 days of treatment, exhibited no significant difference between the four groups. Taken together, these results indicate that treatment of HCA-SX over a period of 90 days results in a reduction in body weight, but did not cause any changes in hepatic and testicular lipid peroxidation, DNA fragmentation, or histopathological changes.     

Regulation of myostatin expression is associated with growth and muscle development in commercial broiler and DMC muscle

Myostatin is a negative regulator of skeletal muscle growth. Muscle tissue is the largest tissue in the body and influences body growth. Commercial Avian broiler chickens are selected for high growth rate and muscularity. Daweishan mini chickens are a slow growing small-sized chicken breed. We investigated the relations between muscle (breast and leg) myostatin mRNA expression and body and muscle growth. Twenty chickens per breed were slaughtered at 0, 30, 60, 90, 120, and 150 days of age. Body and muscle weights were higher at all times in Avian chickens. Breast muscle myostatin expression was higher in Avian chickens than in Daweishan mini chickens at day 30. Myostatin expression peaked at day 60 in Daweishan mini chickens and expression remained higher in breast muscle. Daweishan mini chickens myostatin expression correlated positively with carcass weight, breast and leg muscle weight from day 0 to 60, and correlated negatively with body weight from day 90 to 150, while myostatin expression in Avian chickens was negatively correlated with carcass and muscle weight from day 90 to 150. The results suggest that myostatin expression is related to regulation of body growth and muscle development, with two different regulatory mechanisms that switch between days 30 and 60.     

Neurotransmitter synthesis in poststroke cortical neurogenesis in adult rats

Neurogenesis occurs in the cerebral cortex of adult rats after focal cerebral ischemia. Whether or not the newborn neurons could synthesize neurotransmitters is unknown. To elucidate such a possibility, a photothrombotic ring stroke model with spontaneous reperfusion was induced in adult male Wistar rats. The DNA duplication marker BrdU was repeatedly injected, and the rats were sacrificed at various times after stroke. To detect BrdU nuclear incorporation and various neurotransmitters, brain sections were processed for single/double immunocytochemistry and single/double/triple immunofluorescence. Stereological cell counting was performed to assess the final cell populations. At 48 h, 5 days, 7 days, 30 days, 60 days and 90 days after stroke, numerous cells were BrdU-immunolabeled in the penumbral cortex. Some of these were doubly immunopositive to the cholinergic neuron-specific marker ChAT or GABAergic neuron-specific marker GAD. As analyzed by 3-D confocal microscopy, the neurotransmitters acetylcholine and GABA were colocalized with BrdU in the same cortical cells. In addition, GABA was colocalized with the neuron-specific marker Neu N in the BrdU triple-immunolabeled cortical cells. This study suggests that the newborn neurons are capable of synthesizing the neurotransmitters acetylcholine and GABA in the penumbral cortex, which is one of the fundamental requisites for these neurons to function in the poststroke recovery.     

Physico-chemical properties of a novel (-)-hydroxycitric acid extract and its effect on body weight, selected organ weights, hepatic lipid peroxidation and DNA fragmentation, hematology and clinical chemistry, and histopathological changes over a period of 90 days

Garcinia cambogia-derived (-)-hydroxycitric acid (HCA) is a popular and natural supplement for weight management. HCA is a competitive inhibitor of the enzyme ATP citrate lyase, which catalyzes the conversion of citrate and coenzyme A to oxaloacetate and acetyl coenzyme A (acetyl CoA) in the cytosol. Acetyl CoA is used in the synthesis of fatty acids, cholesterol and triglycerides, and in the synthesis of acetylcholine in the central nervous system. Studies have demonstrated the efficacy of a novel 60% calcium-potassium salt of HCA derived from Garcinia cambogia (HCA-SX, Super CitriMax) in weight management. Results have shown that HCA-SX promotes fat oxidation, enhances serotonin release and availability in the brain cortex, normalizes lipid profiles, and lowers serum leptin levels in obese subjects. Acute oral, acute dermal, primary dermal irritation and primary eye irritation toxicity, as well as Ames bacterial reverse mutation studies and mouse lymphoma tests have demonstrated the safety of HCA-SX. However, no detailed long-term safety of HCA-SX or any other HCA extract has been previously assessed. We evaluated the dose- and time-dependent effects of HCA-SX in Sprague-Dawley rats on body weight, selected organ weights, hepatic lipid peroxidation and DNA fragmentation, hematology and clinical chemistry over a period of 90 days. Furthermore, a 90-day histopathological evaluation was conducted. The animals were treated with 0, 0.2, 2.0 and 5.0% HCA-SX of feed intake and were sacrificed on 30, 60 or 90 days of treatment. The body weight and selected organ weights were assessed and correlated as a % of body weight and brain weight at 90 days of treatment. A significant reduction in body weight was observed in treated rats as compared to control animals. An advancing age-induced marginal increase in hepatic lipid peroxidation was observed in both male and female rats, while no such difference in hepatic DNA fragmentation was observed as compared to the control animals. Furthermore, selected organ weights individually and as a % of body weight and brain weight at 90 days of treatment exhibited no significant difference between the groups. No difference was observed in hematology and clinical chemistry or the histopathological evaluation. Taken together, these results show that 90 day treatment of HCA-SX results in a reduction in body weight, and does not cause any changes in major organs or in hematology, clinical chemistry, and histopathology.     

Neonatal treatment with monosodium glutamate (MSG): structure of the TSH-immunoreactive pituitary cells

Glutamic acid represents the most abundant stimulatory neurotransmitter in the central nervous system. Monosodium glutamate (MSG), subcutaneously administered to newborn rats in the perinatal period, induces lesions in 80 to 90% of the neurocytes of arcuate nuclei in the hypothalamus. These nuclei are the site of production of numerous stimulatory and inhibitory hormones including growth hormone releasing hormone (GHRH). The present studies were performed on male Wistar strain rats, subcutaneously injected on days 2, 4, 6, 8, and 10 of postnatal life with MSG at a dose of 4 mg/g body weight. Eighteen-month-old rats were additionally treated with Ambinon. When the animals reached the ages of 6 or 12 months, their body weight, body length and weight of pituitary were determined. On paraffin sections, using immunohistochemical techniques, TSH-immunoreactive cells were detected and characterised by computerised image analysis. The results were subjected to statistical analysis using Student's t test. The rats which were perinatally treated with MSG and examined after 6 or 12 months of life were obese and shorter than control rats by 7% and 10% respectively. They also exhibited a reduction in the weight of the pituitary of 30% and 40% respectively in the two age groups. The proportion of TSH-immunoreactive cells in the pituitary remained unchanged and amounted to 4.5% in the 6-month-old and 5.4% in the 12-month-old rats, respectively. The number of TSH-positive cells per mm2 area remained unchanged. The area and circumference of the cells in the 12-month-old rats were reduced by 22% and 18%, respectively. Perinatal injury to hypophyseal arcuate nuclei induced by monosodium glutamate injection, was not associated with any significant alterations in pituitary structure, as defined by the proportion of pituitary volume occupied by TSH-immunoreactive cells.     

A histopathological and morphometrical study of femur head cartilage in Wistar rats treated with prednisolone

An analysis was made of histopathological developments in femur head cartilage in a group of Wistar rats receiving a daily intra-muscular injection of 2.5 mg prednisolone. This group was divided into four experimental batches, each consisting of 6 rats. Batches were sacrificed at 15, 30, 60 and 90 days after the start of the experiment. Degeneration of the femur head cartilage was observed from the start of the experiment (15 days), and gave rise to chondrocyte necrosis by 90 days. Structural modifications are shown morphologically and morphometrically.     

Activities of adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) on undernourished and renourished rats' thymus

We studied the effect of administration of a low quality dietary protein, from weaning onwards, on the thymus of undernourished rats and the posterior effect of refeeding with a high quality dietary protein. Changes in thymus weight and the activity of Adenosine Deaminase (ADA) and Purine Nucleoside Phosphorylase (PNP) on thymus, were determined. Wistar rats were suckled in groups of 14-16 per dam since birth to weaning (23 days) to obtain undernutrition. At weaning, a group of 14-16 rats received pre-cooked maize flour (Protein content: 6.5%) for 18 days. One group was sacrificed (M) and the other rats were refed with the casein diet (Protein content: 20%) during 20 days (R). The age-matched control groups were fed stock diet since 40 (C40) and 60 (C60) days of age, respectively. At the end of the experimental period, body (Bw) and thymus weight were determined. ADA and PNP activities were determined in thymocyte suspensions. Highly significant differences in thymus weight-expressed as mg or mg/Bw(0.75)-and the activity of ADA and PNP were observed in rats fed the experimental diet containing maize flour, when compared to the respective age-matched control. No statistical differences were observed between R and C60.The administration of a high quality dietary protein to undernourished weanling rats is capable to reverse the damage produced by the low quality dietary protein on thymus weight and ADA and PNP thymus activities.     

Physico-chemical properties of a novel (—)-hydroxycitric acid extract and its effect on body weight,selected organ weights,hepatic lipid peroxidation and DNA fragmentation,hematology and clinical chemistry,and histopathological changes over a period of 90 days

Garcinia cambogia-derived (—)-hydroxycitric acid (HCA) is a popular and natural supplement for weight management. HCA is a competitive inhibitor of the enzyme ATP citrate lyase, which catalyzes the conversion of citrate and coenzyme A to oxaloacetate and acetyl coenzyme A (acetyl CoA) in the cytosol. Acetyl CoA is used in the synthesis of fatty acids, cholesterol and triglycerides, and in the synthesis of acetylcholine in the central nervous system. Studies have demonstrated the efficacy of a novel 60% calcium-potassium salt of HCA derived from Garcinia cambogia(HCA-SX, Super CitriMax) in weight management. Results have shown that HCA-SX promotes fat oxidation, enhances serotonin release and availability in the brain cortex, normalizes lipid profiles, and lowers serum leptin levels in obese subjects. Acute oral, acute dermal, primary dermal irritation and primary eye irritation toxicity, as well as Ames bacterial reverse mutation studies and mouse lymphoma tests have demonstrated the safety of HCA-SX. However, no detailed long-term safety of HCA-SX or any other HCA extract has been previously assessed. We evaluated the dose- and time-dependent effects of HCA-SX in Sprague-Dawley rats on body weight, selected organ weights, hepatic lipid peroxidation and DNA fragmentation, hematology and clinical chemistry over a period of 90 days. Furthermore, a 90-day histopathological evaluation was conducted. The animals were treated with 0, 0.2, 2.0 and 5.0% HCA-SX of feed intake and were sacrificed on 30, 60 or 90 days of treatment. The body weight and selected organ weights were assessed and correlated as a % of body weight and brain weight at 90 days of treatment. A significant reduction in body weight was observed in treated rats as compared to control animals. An advancing age-induced marginal increase in hepatic lipid peroxidation was observed in both male and female rats, while no such difference in hepatic DNA fragmentation was observed as compared to the control animals. Furthermore, selected organ weights individually and as a % of body weight and brain weight at 90 days of treatment exhibited no significant difference between the groups. No difference was observed in hematology and clinical chemistry or the histopathological evaluation. Taken together, these results show that 90 day treatment of HCA-SX results in a reduction in body weight, and does not cause any changes in major organs or in hematology, clinical chemistry, and histopathology.     

Vasoactive intestinal polypeptide in rat heart atria: the effect of hyperthyroidism

The effects of transient and sustained hyperthyroidism on vasoactive intestinal polypeptide-like immunoreactivity (VIP-LI) levels were studied in the heart atria of developing and adult rats. Newborn rats were divided into 5 groups. Neo-T animals were treated with thyroxine (T4) during postnatal days 1-8 and sacrificed at the age of 60 days. Neo-S rats were treated with T4 during postnatal days 1-60 and sacrificed one day later. Adult-1 and Adult-2 animals received T4 during days 52-60 and were sacrificed 5-6 days and 1 day later, respectively. Control animals were injected with saline. VIP-LI concentrations were determined in extracts from the left and right atria separately. In Neo-S and Adult-2 rats, spontaneous heart rate, the weight of both atria and total T4 serum levels were significantly enhanced, while their body weight was decreased. The ratio atria weight to body weight was significantly increased in all groups except for Adult-1 animals. Hyperthyroidism led to a significant decrease in VIP-LI levels in both atria of Neo-S and Neo-T rats. Hyperthyroidism induced in adult rats also decreased VIP-LI levels in both atria. However, this change was only transient. In conclusion, our data have provided new evidence that hyperthyroidism induced during the early neonatal period interferes with the development of VIP-ergic innervation in rat atria. The period of the first few postnatal days seems to be essential for this effect, since VIP-LI concentrations in 60-day-old animals did not significantly differ between Neo-S and Neo-T atria.     

Effect of vitamin D deficiency on skeletal development during early growth in the rat

To define the role of vitamin D in early development, female weanling rats were grown to maturity on a vitamin D-deficient diet and mated with normal males. At Day 20 of pregnancy the weight and total body calcium of fetuses were determined. At various times after parturition, pups were sacrificed. Plasma samples were analyzed for calcium and phorphorus, and femurs were characterized as to volume, dry weight, ash weight, and total calcium. The results indicate that vitamin D deficiency with its accompanying hypocalcemia does not impair placental transfer of calcium nor weight gain of the fetus. Vitamin D deficiency does appear to increase calcium accumulation in the fetus. After parturition vitamin D is functional in maintaining a normocalcemia as early as 3 days postpartum and its importance increases with age of the neonate. Bone mineralization is clearly disrupted by Day 14 as judged by calcium content per unit bone volume and the severity of the defect increases with age. Both vitamin D and normal concentrations of calcium and phosphorus appear to be essential for proper skeletal development during early growth postpartum.     

Effects of experimental hyperadrenocorticism on the growth of the femur and tibia in normal and bipedal rats

Daily subcutaneous injections of glucocorticoid preparations have been shown to produce clinical signs of hyperadrenocorticism which resulted in interference with the growth of rats, shown by measurements both of body weight and of the length of long bones. The purpose of this study was to see if increased, intermittent, compressive forces, produced by experimental bipedalism, would mitigate the negative effects of cortisone injections on long bone growth and if there would be a difference in reaction between male and female rats. Male and female Sprague-Dawley rats were used for control, cortisone-injected, and cortisone-injected plus bipedal groups. Experimental bipedalism was produced at 10 days of age; cortisone injections began at 30 days of age; all animals were sacrificed at 65 days of age. Tibial and femoral lengths were measured. The results do not support the hypothesis that bipedalism can be instrumental in mitigating the effects of hyperadrenocorticism on hindlimb long bone growth.     

Expression of calcium-binding protein regucalcin mRNA in fetal rat liver is stimulated by calcium administration

The expression of hepatic calcium-binding protein regucalcin mRNA in fetal rats was investigated. The alteration in regucalcin mRNA levels was analyzed by Northern blotting using liver regucalcin cDNA (0.9 kb with complete open reading frame). Hepatic regucalcin mRNA levels were progressively increased with fetal development; the mRNA was clearly expressed at 15 and 21 days of pregnancy but only slightly at the 8 days. Meanwhile, -actin mRNA levels in the fetal liver were remarkable at 8 and 15 days of pregnancy. The fetal liver regucalcin mRNA levels at 15 days of pregnancy were significantly decreased by overnight-fasting of maternal rats. The oral administration of calcium chloride (50 mg Ca/100 g body weight) to maternal rats at 15 days of pregnancy caused a remarkable elevation (about 2 fold) of regucalcin mRNA levels in the fetal liver; this increase was seen 60 and 180 min after the calcium administration. After birth, regucalcin mRNA was increasingly expressed in the livers of newborn and weanling rats, while hepatic -actin mRNA expression was not appreciably altered with increasing ages. These findings demonstrate that the expression of hepatic regucalcin mRNA is increased with fetal development, and that the gene expression may be stimulated by the ingestion of dietary calcium.     

Myelin Deficits Produced by Early Postnatal Exposure to Inorganic Lead or Triethyltin Are Persistent

Abstract: Long-Evans rat pups were exposed to either inorganic lead (400 mg Pb as lead acetate/kg body weight/day) or triethyltin sulfate (1.0 mg/kg body weight/day), by gastric intubation, from 2 days through 29 days of age. The rats were then weaned and placed on standard lab chow ad libitum. At 30 days of age, leadtreated rats exhibited statistically significant decreases in body and brain weights (22% and 17%, respectively), and the concentration of forebrain myelin was significantly reduced, by 21% relative to the 4.9 mg myelin protein/g brain in control rats. Although these animals recovered from the body weight deficits after several months, the deficits in brain weight and myelin concentration were still present at 120 days of age. This suggests that the lead-induced myelin deficits were permanent. Lead levels in brain, which were maximal at 30 days of age when the treatment was terminated, decreased more slowly than in other organs and were still 30% of maximal levels at 120 days of age. Triethyltin-treated animals also had significantly decreased body and brain weights (20% and 11%, respectively) at 30 days of age, and an even more severe reduction in forebrain myelin concentration (33%). These animals also regained a normal body weight by 120 days of age, but again the deficits in brain weight and myelin concentration persisted. Tin levels in brain and other organs had decreased to control levels by 60 days of age. Animals malnourished by maternal deprivation to match the body weights of the treated animals had myelin deficits that were less severe than those in the treated animals at 30 days of age (approximately 11% less than controls); however, these myelin deficits also persisted throughout the subsequent 90-day recovery period examined. The apparent lack of recovery from CNS myelin deficits produced by neonatal exposure to different heavy metals or to malnutrition reemphasizes the vulnerability of the developing nervous system to a wide range of metabolic insults.     

The response of circulating parameters of bone mineral metabolism to ethanol- and EDTA-induced hypocalcemia in the rat

The mechanism of the acute hypocalcemia that follows acute ethanol administration has not been established. Measurements of parathyroid hormone (PTH) performed during this hypocalcemia reveal conflicting results. We compared the response of ionized calcium (Ca²⁺), immunoreactive PTH and bone Gla protein (BGP) after ethanol- and EDTA-induced hypocalcemia. 103 male Sprague Dawley rats each weighing approximately 300 g received ethanol and 100 rats of similar weight received EDTA. In each of these studies the animals were divided into experimental and control groups. The ethanol-treated rats received ethanol, 2 g/kg body weight, by ip injection and the EDTA-treated rats received 100 mg EDTA/kg body weight by im injection. Controls received normal saline by the corresponding route of administration. Rats were sacrificed at 0, 30, 60, 90, 180 and 360 min for the measurement of the above parameters. In both experimental groups Ca²⁺ levels were significantly reduced to the same degree by 30 min with return to control values by 360 min. There was no significant difference in immunoreactive PTH, and BGP between control and ethanol-treated groups. In the EDTA-treated rats, however, PTH values were significantly increased at 30 (P < 0.005) and BGP at 60 and 90 minutes (P < 0.005) vs. control. Therefore acute ethanol administration appears to blunt the PTH response to hypocalcemia. A direct inhibitory effect of ethanol on osteoblast function ie BGP production cannot be excluded. In addition, PTH may stimulate BGP.