A Chinese Traditional Therapy for Bleomycin-Induced Pulmonary Fibrosis in Mice.

Pulmonary fibrosis is a chronic and fatal disease of lung tissue with high incidence and mortality in the world. The exploration of effective treatment for pulmonary fibrosis remains an urgent challenge. In our study, Qingfei Xieding was investigated as a novel Chinese traditional patent medicine against pulmonary fibrosis. A pulmonary fibrosis mouse model was constructed by injecting with bleomycin sulfate. Following Qingfei Xieding administration, lung samples were collected to assess pulmonary phenotype changes by analyzing lung coefficient, wet/dry, and histopathologic section. Levels of nitric oxide (NO), hydroxyproline (HYP), malondialdehyde (MDA), and total antioxidant capacity were measured to evaluate the degree of oxidation. A single-cell gel electrophoresis (SCGE) assay was used to evaluate bleomycin-induced DNA damage. Western blotting and real-time quantitative PCR were performed to determine the abundance of inducible nitric oxide synthase (iNOS), connective tissue growth factor (CTGF), alpha smooth muscle actin (α-SMA), and fibronectin (FN). In the present study, Qingfei Xieding administration significantly attenuated bleomycin-induced pulmonary fibrosis in mice by reducing lung coefficient, wet/dry, NO, HYP, and MDA as well as the expression of iNOS, CTGF, α-SMA, FN, and DNA damage. The results indicated that Qingfei Xieding is effective to resist oxidative damage and histopathologic lesion, serving a protection role on bleomycin-induced pulmonary fibrosis.

Appraisal on the wound healing activity of different extracts obtained from Aegle marmelos and Mucuna pruriens by in vivo experimental models.

AIM: The use of a simple and reproducible model is inevitable for an objective statement of the effects of external factors on wound healing. Hence, the present study was conducted to evaluate wound healing activities of sequential different extracts of Aegle marmelos leaves (AM) and Mucuna pruriens seeds (MP) by in vivo experimental models. MATERIALS AND METHODS: Wistar albino rats were subjected to excision, incision and dead space wounds measuring approximately 250 mm2, 3 cm and implanting sterilized polyvinyl chloride tube on the back of each rat near either side of the vertebral column respectively. The experimental animals were randomized into eight groups (n = 6), control, standard and treatment groups. Hydrogel of different extracts were applied topically once daily. The parameters observed were percentage of wound contraction, epithelization period, tensile strength, hydroxyproline content of the granulation tissue, and histological changes during wound healing. RESULTS: The statistical study revealed that in excision, incision, and dead space wound models all formulations have significant (P < 0.01) wound healing potential. However, methanolic extract formulation was found to be superior to all other treatments as evidenced by rapid wound contraction, lesser number of days required for complete epithelization, increased tensile strength and significant increase in hydroxyproline content. CONCLUSIONS: As compared to the reference standard treated group the wound healing process of the experimental groups was decelerated. All extracts obtained from AM and MP facilitated the wound healing process in all experimental models.

Effects of zoledronate on irradiated bone in vivo: analysis of the collagen types I, V and their cross-links lysylpyridinoline, hydroxylysylpyridinoline and hydroxyproline.

Radiotherapy can lead to a reduction of bone density with an increased risk of pathological fractures. Bisphosphonates may represent a preventive treatment option by increasing the density of anorganic bone mineral. Yet it is unknown how bisphosphonates act on irradiated collagen cross-links, which play an essential role for the mechanical stability of bone. The aim of this study was to evaluate the effects of zoledronate on bone collagens and their cross-links after irradiation. The right femur of 37 rats was irradiated with a single dose of 9.5 Gy at a high dose rate using an afterloading machine. Half of the rats (n=18) received additionally a single dose zoledronate (0.1 mg/kg body weight). Fourteen and 100 days after irradiation the femora were collected for histologic evaluation and determination of the collagen cross-links lysylpyridinoline, hydroxylysylpyridinoline, and hydroxyproline. The collagen types were characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Fourteen days after treatment the lysylpyridinoline levels of all treatment groups were significantly lower compared to the untreated control. After 100 days, in the combined radiotherapy+zoledronate group significantly lower lysylpyridinoline values were determined (p=0.009). Radiotherapy and/or zoledronate did not change significantly the level of hydroxylysylpyridinoline. The concentration of hydroxyproline was 14 days after irradiation significantly higher in the combined treatment group compared to the control. No significant differences were observed 100 days after treatment. Zoledronate does not have the ability to restore the physiological bone collagen cross-link levels after radiotherapy. However, this would be necessary for regaining the physiological mechanical stability of bone after irradiation and therefore to prevent effectively radiation-induced fractures.

[Diabetes mellitus ulcers treatment with Bletilla striata polysaccharide].

The aim of this study was to evaluate the efficacy of Bletilla striata polysaccharide on diabetes mellitus ulcers. Diabetes mellitus animal model was established by single ip injection of streptozotocin (STZ, 50 mg x kg(-1)) with the criteria of blood glucose > or = 16.7 mmol x L(-1) after 72 h. 4 weeks after STZ injection, each animal received two full thickness incisional wounds (1.8 cm in diameter). The wounds then were divided into B. striata polysaccharide group and PBS group. Wound closure rate, fibroblast (FB) infiltration, hydroxyproline (OHP) content and myeloperoxidase (MPO) levels were examined on day 3, 7, 14, 21 post wound. The treatment of B. striata polysaccharide significantly facilitated diabetes mellitus ulcers healing compared to PBS group. Histological analysis showed that B. striata polysaccharide markedly increased inflammatory cell infiltration in wound area. The herb also strongly evaluation of FB, OHP demonstrated a significantly increased in B. striata polysaccharide group. B. striata polysaccharide group promoted wound closure by means of enhanced inflammatory cell infiltration and re-epithelialization, and the promotion of FB and OHP levels.

Taurine attenuates radiation-induced lung fibrosis in C57/Bl6 fibrosis prone mice.

INTRODUCTION: The amino acid taurine has an established role in attenuating lung fibrosis secondary to bleomycin-induced injury. This study evaluates taurine's effect on TGF-beta1 expression and the development of lung fibrosis after single-dose thoracic radiotherapy. METHODS: Four groups of C57/Bl6 mice received 14 Gy thoracic radiation. Mice were treated with taurine or saline supplementation by gavage. After 10 days and 14 weeks of treatment, TGF-beta1 levels were measured in serum and bronchoalveolar lavage fluid (BALF). Lung collagen content was determined using hydroxyproline analysis. RESULTS: Ten days post radiotherapy, serum TGF-beta1 levels were significantly lower after gavage with taurine rather than saline (P = 0.033). BALF TGF-beta1 at 10 days was also significantly lower in mice treated with taurine (P = 0.031). Hydroxyproline content was also significantly lower at 14 weeks in mice treated with taurine (P = 0.020). CONCLUSION: This study presents novel findings of taurine's role in protecting from TGF-beta1-associated development of lung fibrosis after thoracic radiation.

Aquilegia vulgaris extract attenuates carbon tetrachloride-induced liver fibrosis in rats.

Six groups of male Wistar rats were treated as follows: in groups II, III and V liver damage was induced by CCl(4) (per os, 1590 mg/kg b.w.day) given 2 days a week for 6 weeks; group III was treated simultaneously with ethanol extract of Aquilegia vulgaris (100 mg/kg b.w.day) for 6 weeks; group V with silymarin, positive control, at a dose of 100 mg/kg b.w.day for 6 weeks; and groups IV and VI received only the extract or silymarin, respectively. Microsomal lipid peroxidation in the liver increased following CCl(4) treatment by 61-213% and was not changed significantly by the extract. The effect of silymarin was more pronounced, 19-52% decrease in the lipid peroxidation level. Hepatic glutathione was depleted by 22% in CCl(4)-treated rats. The extract tested did not change this parameter. The activity of antioxidant enzymes was significantly reduced after CCl(4) administration, by 42-63%. Co-administration of the extract or silymarin resulted in significant increase in these enzymes activity; however, the basal level was not reached. Hepatic hydroxyproline concentration was elevated over 5-fold in comparison with controls. Co-administration of the extract or silymarin decreased the level of hydroxyproline by 66% and 55%, respectively. Activity of serum hepatic enzymes was elevated in rats treated with CCl(4) by 47-8700%. Both the extract and silymarin reduced significantly these enzymes' activity. The extract caused a fall in bilirubin and cholesterol level in rats treated with CCl(4) by 42% and 17%, respectively. Histopathological examination revealed less-severe fibrosis in rats co-administered the extract or silymarin when compared to animals treated with CCl(4) alone.

Wound healing properties of Carica papaya latex: in vivo evaluation in mice burn model.

ETHNOPHARMACOLOGICAL RELEVANCE: Carica papaya is traditionally used to treat various skin disorders, including wounds. It is widely used in developing countries as an effective and readily available treatment of various wounds, particularly burns. THE AIM OF THE STUDY: This study was aimed at investigating the healing efficiency of papaya latex formulated as 1.0 and 2.5% hydrogels. MATERIALS AND METHODS: Burns were induced in Swiss albino mice divided into five groups as following; Group-I (negative control) received no treatment. Group-II was treated with Carbopol 974P NF empty gel. Groups-III and -IV were treated with Carbopol gel containing 1.0 and 2.5% of dried papaya latex, respectively. Group-V (positive control) received the standard drug (silver sulphadiazine and chlorhexidine gluconate cream). The efficacy of treatment was evaluated based on the hydroxyproline content, wound contraction and epithelialization time. RESULTS: Hydroxyproline content was found to be significantly increased in the Group-III. Significant increase in percentage wound contraction was observed from day 12 in Group-IV and from day 20 in Groups-III and -V. The epithelialization time was found to be the shortest in Group-IV. CONCLUSION: It may be concluded that papaya latex formulated in the Carbopol gel is effective in the treatment of burns and thus supports its traditional use.

Inhibitory effect of Solanum nigrum on thioacetamide-induced liver fibrosis in mice.

AIM: Solanum nigrum (Solanaceae) has been used in traditional folk medicine for its hepatoprotective agent. The purpose of this study was to investigate the effects of Solanum nigrum extract (SNE) on thioacetamide (TAA)-induced liver fibrosis in mice. MATERIALS AND METHODS: Hepatic fibrosis was produced by TAA (0.2 g/kg, i.p.) three times a week for 12 weeks. Mice in the three TAA groups were treated daily with distilled water and SNE (0.2 or 1.0 g/kg) via gastrogavage throughout the experimental period. RESULTS: SNE reduced the hepatic hydroxyproline and alpha-smooth muscle actin protein levels of TAA-treated mice. SNE inhibited TAA-induced collagene (alpha1)(I) and transforming growth factor-beta1 (TGF-beta1) mRNA levels in the liver. Histological examination also confirmed that SNE reduced the degree of fibrosis caused by TAA treatment. CONCLUSION: Oral administration of SNE significantly reduces TAA-induced hepatic fibrosis in mice, probably through the reduction of TGF-beta1 secretion.

Wound healing activity of Persea americana (avocado) fruit: a preclinical study on rats.

OBJECTIVE: Avocado (Persea americana) oil is rich in nutrient waxes, proteins and minerals, as well as vitamins A, D and E. It is an excellent source of enrichment for dry, damaged or chapped skin. This study aimed to evaluate the wound-healing activity of fruit extract of Persea americana in rats. METHOD: The effect of topical and oral administration of Persea americana fruit extract (300 mg/kg/day) on excision and dead space wound models was evaluated. The rats used in the excision wound model were divided into four groups of five each and received either topical or oral treatment. The rats used in the dead space wound model were divided into two groups of five each and were treated orally. Healing was assessed by the rate of wound contraction, period of epithelialisation, granulation tissue weight and hydoxyproline content. RESULTS: In the excision wound model, complete healing (full epithelialisation) was observed on average on day 14 in the rats who receive oral or topical treatment. In contrast, the controls took approximately 17 days to heal completely. The extract-treated wounds were found to epithelialise faster than the controls (p < 0.001). Wet and dry granulation tissue weight and the hydroxyproline content of the tissue obtained from extract-treated animals used in the dead space wound model were significantly higher (p < 0.05) compared with the controls. CONCLUSION: Rate of wound contraction, epithelialisation time together with the hydroxyproline content and histological observations support the use of Persea americana in the management of wound healing.

Topical diphenylhydantoin sodium can improve healing in a diabetic incisional animal wound model.

OBJECTIVE: Anecdotally, topical application of diphenylhydantoin sodium (DpH) (phenytoin) has been shown to aid wound healing. We previously reported improved healing following topical infiltration of DpH in a healthy animal wound model. This study evaluates its effect on an incisional wound model in diabetic animals. METHOD: Twenty-five male Sprague-Dawley rats were rendered diabetic by a single intraperitoneal injection of streptozotocin. Two caudal and two cephalad wounds were made on the dorsal surface. A polyvinyl alcohol sponge was placed in a subcutaneous pocket created proximal to both cephalad wounds. Each wound was either treated topically with 10mg DpH in a 200microl carrier or an equal volume of the saline vehicle (control) on the day of wounding and days 3 and 6 post-incision. The animals were sacrificed on day 10. The breaking strength of fresh and fixed wounds was determined by tensiometry, and the hydroxyproline content was determined spectrophotometrically. RESULTS: There was a significant overall increase in both fresh (24%) and fixed (18%) wound-breaking strength of the DpH-treated wounds when compared with the controls (p<0.05). This was associated with an increase in collagen synthesis as indicated by the increased hydroxyproline content in the DpH-infiltrated sponges when compared with the controls. CONCLUSION: Our data suggest that topical DpH improves healing in a diabetic wound model. Topical administration of DpH has the potential to accelerate diabetic wound healing and should be evaluated in human diabetic wounds.

Inhibitory effects of soy isoflavones on cardiovascular collagen accumulation in rats.

Oxidative stress is a major cause of cardiovascular tissue fibrosis. We evaluated the effects of daily doses of soy isoflavones, genistein and daidzein on cardiovascular tissue fibrosis in Otsuka Long-Evans Tokushima Fatty (OLETF) diabetic rats and Long-Evans Tokushima Otsuka (LETO) non-diabetic rats as a severe or mild oxidative stress model, respectively. Glucose and lipid metabolisms did not improve with genistein or daidzein treatment. However, genistein decreased hydroxyproline concentrations in the heart. Hydroxyproline reductions as a result of genistein were mildly stronger than those of daidzein. Thus, genistein significantly suppressed the progression of myocardial fibrosis in LETO rats despite the insignificant changes in OLETF rats. Although a daily dosage of isoflavone was not sufficient to prevent tissue fibrosis under marked oxidative stress in the early stage of diabetes, isoflavones might promise significant clinical benefits by reducing oxidative stress in the heart during aging.

Wound-healing activity of Morinda citrifolia fruit juice on diabetes-induced rats.

OBJECTIVE: Morinda citrifolia L. is a traditional Polynesian medicinal plant which is apparently useful for bowel disorders, skin inflammation, infection, mouth ulcers and wound healing. This study aimed to evaluate the wound-healing activity of Morinda citrifolia fruit juice in streptozotocin-induced diabetic rats. METHOD: An excision wound model was used. The animals were weight-matched and placed into three groups (n = 6 per group). Group 1 animals served as normal controls, while animals in groups 2 and 3 served as diabetic controls and experimental diabetic animals respectively. All animals were anaesthetised and a full-thickness excision wound (circular area of 300 mm2 and 2 mm deep) was created. Group 3 animals were given the juice of Morinda citrifolia fruit (100 ml per kilogram of body weight) in their drinking water for 10 days. Wound area measurements were taken on days 1, 5 and 11. Blood samples were collected simultaneously for glucose measurement. Granulation tissue that had formed on the wound was excised on day 11 and processed for histological and biochemical analysis. RESULTS: The wound area of the Morinda citrifolia-treated group reduced by 73% (p < 0.001) when compared with the diabetic controls (63%). Significant increases in the weight of granulation tissue (p < 0.001) and hydroxyproline content (p < 0.00 1, 92.16 +/- 4.02) were observed. The protein content was moderately high. Histological studies showed that collagen was laid down faster in the experimental diabetic animals than in the normal control and diabetic control groups. Fasting blood glucose values in the diabetic experimental group had reduced by 29% (p < 0.00 1) compared with the diabetic control animals. There was a good correlation between the wound contraction rate and blood glucose values. CONCLUSION: This study demonstrates that the juice of Morinda citrifolia fruit significantly reduces blood sugar levels and hastens wound healing in diabetic rats.

An herbal formula, CGX, exerts hepatotherapeutic effects on dimethylnitrosamine-induced chronic liver injury model in rats.

AIM: To evaluate the therapeutic effect of Chunggan extract (CGX), a modified traditional Chinese hepatotherapeutic herbal, on the dimethylnitrosamine (DMN)-induced chronic liver injury model in rats. METHODS: Liver injuries were induced in Wistar rats by injection of DMN (ip, 10 mg/mL per kg) for 3 consecutive days per week for 4 wk. The rats were administered with CGX (po, 100 or 200 mg/kg per day) or distilled water as a control daily for 4 wk starting from the 15(th) d of the DMN treatment. Biochemical parameters (serum albumin, bilirubin, ALP, AST and ALT), lipid peroxides, hydroxyproline, as well as histological changes in liver tissues were analyzed. In addition, gene expression of TNF-alpha, TGF-beta, TIMP-1, TIMP-2, PDGF-beta, and MMP-2, all of which are known to be associated with liver fibrosis, were analyzed using real-time PCR. RESULTS: CGX administration restored the spleen weight to normal after having been increased by DMN treatment. Biochemical analysis of the serum demonstrated that CGX significantly decreased the serum level of ALP (P < 0.05), ALT (P < 0.01), and AST (P < 0.01) that had been elevated by DMN treatment. CGX administration moderately lowered lipid peroxide production and markedly lowered hydroxyproline generation caused by DMN treatment in accordance with histopathological examination. DMN treatment induced a highly up-regulated expression of TNF-alpha, TGF-beta, TIMP-1, TIMP-2, PDGF-beta, and MMP-2. Of these, the gene expression encoding PDGF-beta and MMP-2 was still further enhanced 2 wk after secession of the 4-wk DMN treatment, and was remarkably ameliorated by CGX administration. CONCLUSION: CGX exhibits hepatotherapeutic proper-ties against chronic hepatocellular destruction and consequential liver fibrosis.

Effect of herbal extract mixture on menopausal urinary incontinence in ovariectomized rats.

The decline of estrogen production after menopause is contributing factor to urinary incontinence (UI), and particularly stress urinary incontinence (SUI). We determined the preventive effects of herbal extract mixture (HEM) on UI in ovariectomized Sprague Dawley rats. Female 9-weeks old rats were ovariectomized and treated with HEM (2.2, 11, or 55 mg/kg/day) for 8 weeks. The index of urinary bladder weight to body weight in the HEM and non-ovariectomized and non-treated (SHAM) groups were slightly higher than the ovariectomized, non-treated group (OVX). The contraction index of acetylcholine to KCl on detrusor smooth muscle strips in the HEM groups showed a dose-dependent recovery. HEM treatment also significantly improved collagen levels, as shown by Masson trichrome staining, as well as hydroxyproline levels in the urinary bladder. Serum estradiol levels in the HEM groups were higher than the OVX group. In conclusion, HEM increased estradiol levels in serum and improved factors related to urinary incontinence. The improvements in estradiol levels were related to changes in urinary incontinence.

[Effect of salmon calcitonin on bone mineral density and calcium-phosphate metabolism in chronic hemodialysis patients with secondary hyperparathyroidism]. / Wplyw lososiowej kalcytoniny na gestosc mineralna kosci oraz metabolizm wapnia i fosforu u chorych z wtórna nadczynnoscia przytarczyc przewlekle hemodializowanych.

UNLABELLED: The aim of the study was to evaluate the effect of salmon calcitonin on bone mineral density, parathyroid and thyroid C cells, and calcium-phosphate metabolism in chronic hemodialysis patients with uremic hyperparathyroidism. Forty five patients with serum 1-84 PTH >220 pg/ml were divided into 2 groups: group I (n = 25), treated with intranasal salmon calcitonin (200 IU, thrice a week) and control group II (n = 20). Patients received calcium carbonate (up to 6 g/d) alone or with aluminum hydroxide (up to 3 g/d) as phosphate binders; dialysate calcium was 1.75-2 mmol/l. The observation period was 12 months. The following parameters were measured: bone mineral density (BMD) with dual-energy X-ray absorptiometry in: lumbar spine (L2-L4), femoral neck and total body, before and after the study; serum endogenous calcitonin, before and after the study; serum PTH, alkaline phosphatase and total hydroxyproline, before and after 1, 3, 6, and 12 months; and serum calcium and phosphate monthly. During 12 months of the study, a substantial reduction in BMD was observed in all examined regions in group II (-2.8 +/- 2.1%; p<0.01 in L2-L4, -2.4 +/- 2.0%; p<0.01 in femoral neck, and -1.9 +/- 1.4%; p<0.01 in total body), whereas in group I a slight increase of bone mineral was noted, however insignificant. The inhibition of bone resorption was accompanied by a marked decrease in serum hydroxyproline. No changes in parathyroid activity were noted nor any decrease in serum phosphate. The treatment had no influence on serum endogenous calcitonin; initial concentrations were elevated in 47% of patients. CONCLUSION: Intranasal salmon calcitonin: 1) has no influence on bone mineralization in dialysis patients with uremic hyperparathyroidism; 2) has no significant effect on serum phosphate concentration; 3) provided adequate calcium supplementation doesn't stimulate parathyroid glands; 4) has no influence on endogenous calcitonin secretion.

Glycine prevents hepatic fibrosis by preventing the accumulation of collagen in rats with alcoholic liver injury.

We studied the effect of administering glycine, a non-essential amino acid, on liver collagen content and its characteristics in experimental hepatotoxic Wistar rats. All the rats were fed standard pellet diet. Hepatotoxicity was induced by orally administering ethanol (7.9 g kg(-1)) for 30 days. Control rats were given isocaloric glucose solution. Glycine was administered subsequently at a dose of 0.6 g kg(-1) po every day, along with alcohol for the next 30 days. Alcohol administration significantly elevated the levels of liver hydroxyproline and total collagen content, cross-linked fluorescence, shrinkage temperature and lipid peroxidation, whereas it significantly decreased the solubility of liver collagen as compared with the control rats. Simultaneous glycine supplementation to alcohol-fed rats significantly reduced the levels of liver hydroxyproline and total collagen content, cross-linked fluorescence, shrinkage temperature and lipid peroxidation and enhanced the solubility of liver collagen as compared with the unsupplemented alcohol-fed rats. In conclusion, administration of glycine had a positive influence both on the quantitative and qualitative properties of hepatic collagen in alcoholic liver injury.

A caffeine diet can alter the mechanical properties of the bones of young ovariectomized rats.

The general public widely consumes caffeine which is contained in various foods, beverages, and over-the-counter medications. The relationships between caffeine intake and bone fractures is controversial. Therefore, the aim of the current study was to determine what effects, if any, caffeine intake in early life exerts on mechanical properties and mineral contents of bone in growing ovariectomized rats. A total of 8 dams with pups were divided into two groups. Group 1 was fed a 20% protein diet. Group 2 was fed a 20% protein diet supplemented with caffeine (4 mg/100 g). The respective diets were fed to the dams during lactation and to the pups continuously after weaning on day 22 until the end of the experimental period. On day 32, offspring from both groups were ovariectomized. On day 52, the rats were sacrificed and the femora removed. The biomechanical properties of the femora were determined by three-point bend testing to failure at a rate of 2 mm/min, with continuous data sampling at 10 samples/s. The properties determined included the modulus of elasticity, yield load, yield stress, ultimate load, ultimate stress, and the second moment of area. The caffeine group exhibited a decrease in the various mechanical properties (ranging from approximately 7 to 20%), except for yield strain and moment of inertia. The decreases in maximum stress and elastic modulus values were significant. Calcium, magnesium, and phosphorous values for the caffeine group were significantly decreased. These results suggest that the bone in the caffeine group is weaker and less stiff, with greater deformation under applied loading. It could be concluded that caffeine intake during the early growing period affects the mechanical properties of bone.

Calcium supplementation suppresses bone resorption in early postmenopausal women.

In order to establish whether calcium supplementation suppresses bone resorption in early postmenopausal women and whether any response is related to calcium absorption status, we studied 22 healthy women (median age 52 years) all within 5 years of the menopause. Urine was collected between 9.00 p.m. and 9.00 a.m., and 9.00 a.m. and 9.00 p.m., (2 days) and a fasting blood and spot urine sample was obtained at 9 a.m. On the first day, 5 microCi of 45Ca in 250 ml water with 20 mg calcium carrier as the chloride was given at 9.00 a.m. and a further blood sample was obtained at 10.00 a.m. to measure calcium absorption. A 1 g calcium load was given at 9.00 p.m., immediately before the second 24-hour urine collection. There was a rise in plasma ionized calcium (1.18 +/- 0.010 mmol/liter versus 1. 21 +/- 0.011 mmol/liter, P < 0.01) and a fall in plasma PTH (4.2 +/- 0.34 pmol/liter versus 3.5 +/- 0.31 pmol/liter, P < 0.01) from baseline after the calcium load, and a trend for the magnitude of the change in PTH to be inversely related to calcium absorption (r = -0.33, P = 0.13). In the fasting spot urine samples, there were falls in hydroxyproline (OHPr/Cr; 14.6 +/- 0.71 versus 12.6 +/- 0.83, P < 0.001), pyridinoline (Pyr/Cr; 75 +/- 2.8 versus 70 +/- 3.5, P < 0.05), and deoxypyridinoline (Dpd/Cr; 22.7 +/- 1.2 versus 19.5 +/- 1. 1, P < 0.005) after the calcium load. The calcium load suppressed urinary Dpd/Cr between 9.00 p.m. and 9.00 a.m. (P < 0.005), but not between 9.00 a.m. and 9.00 p.m. We conclude that acute administration of a 1 g calcium load suppresses bone resorption in early postmenopausal women, probably by decreasing PTH secretion.

The effect of chlorothiazide on bone-related biochemical variables in normal post-menopausal women.

OBJECTIVE: To evaluate the effects of short-term administration of chlorothiazide on fasting urinary hydroxyproline, an index of bone resorption, and other bone-related biochemical parameters in normal post-menopausal women. DESIGN: Subjects served as their own control before and after chlorothiazide treatment. SETTING: Subjects were recruited by advertisement. PARTICIPANTS: Thirteen healthy post-menopausal women with a mean age of 65 years. INTERVENTION: Each subject was given chlorothiazide 500 mg bd po for 7 days. Fasting blood and urine samples were obtained immediately before the commencement of chlorothiazide (day 1) and 2 and 7 days after starting chlorothiazide. RESULTS: Chlorothiazide decreased the urinary calcium/creatinine (mean value day 1, 0.267; day 2, 0.143; day 7, 0.135; P < 0.001) and hydroxyproline/creatinine (day 1, 0.0192; day 2, 0.0145; day 7, 0.0139; P < 0.02) molar ratios. CONCLUSION: Chlorothiazide decreases fasting urinary hydroxyproline, a marker of bone resorption in post-menopausal women. This observation supports a potential role for thiazide diuretics in the prevention of osteoporosis. The observed fall in urinary hydroxyproline is of the same order as that seen after treatment with estrogen or calcium supplements.