Grafting of tooth extraction socket with inorganic bovine bone or bioactive glass particles: comparative histometric study in rats.

Purpose: To compare histometrically, in rats, the bone healing after grafting the incisor extraction sockets with inorganic bovine bone or bioactive glass particles.

Material: The volume fraction of grafted materials and alveolar healing components was estimated in histologic images at the end of the second and ninth weeks postoperatively by a differential point-counting method.

Results: Both materials were histologically observed partially filling the cervical alveolar third and, although evoking neither a foreign body reaction nor a persisting inflammatory response, delayed new bone formation in trial areas around their particles.

Alveolar wound healing after implantation with a pool of commercially available bovine bone morphogenetic proteins (BMPs): a histometric study in rats.

The capacity of a commercially available pool of bovine bone morphogenetic proteins (BMPs) to stimulate osteogenesis in the rat alveolar healing was investigated by histometric analysis. Male rats were anesthetized and had their upper incisor extracted. A pool of purified bovine BMPs adsorbed to microgranular resorbable hydroxyapatite was agglutinated with bovine collagen and saline before implantation into the alveolar socket.

Biocompatibility of natural latex implanted into dental alveolus of rats.

The present study investigated the biocompatibility of a biopolymer based on vegetable latex extracted from the Hevea brasiliensis rubber tree, implanted into the bony alveolar cavity after dental extraction in rats. A granule of latex (area = 0.25 +/- 0.

Prolonged deleterious effects of neonatal handling on reproductive parameters of pubertal male rats.

The purpose of the present study was to investigate the long-lasting effects of neonatal handling on reproductive parameters of male rats. Neonatal handling (pups separated from their mothers, kept isolated at environmental temperature for 20 min and submitted to 1 min of tactile stimulation) was applied from post partum Days 1 to 14 (a stress-hyporesponsive period, SHRP) and the animals were killed at puberty (61 days of age). The number of mature spermatids and the daily sperm production were estimated in homogenates from the right testes and cauda epididymidis.

Bone healing in osteoporotic female rats following intra-alveolar grafting of bioactive glass.

We have investigated the effect of ovariectomy combined with a low Ca diet on bone healing following the implantation of bioactive glass into extraction sockets, in rats. Ovariectomized rats received a low Ca diet from the day of surgery until sacrifice while sham-operated animals were fed a standard laboratory chow. Two weeks after surgery the upper incisors were extracted and the alveolar sockets in both groups were partially filled with a particulate bioglass (PerioGlas).

Comparison between two experimental protocols to promote osteoporosis in the maxilla and proximal tibia of female rats.

The effects of two experimental protocols (ovariectomy associated or not with a low calcium diet) used to promote osteoporosis in the rat maxilla and proximal tibia were compared 5 and 11 weeks after surgery. Female Wistar rats were ovariectomized or sham-operated. Half of the ovariectomized rats were fed a low Ca++ diet (ovx*) and the remaining ovariectomized (ovx) and sham animals received a standard chow.

Histometric study of socket healing after tooth extraction in rats treated with diclofenac.

The purpose of the present study was to investigate if diclofenac administration interferes with the time course of alveolar wound healing in rats. Forty-two Wistar rats were used, 21 rats received 10 mg/kg/day of diclofenac one day before and 4 days after extraction of the right maxillary incisors and 21 rats received saline. The animals were sacrificed 7, 14 and 21 days after tooth extraction.

Antireproductive effect of the calcium channel blocker amlodipine in male rats.

The purpose of the present study was to investigate whether treatment of male rats with the calcium antagonist amlodipine, used in the treatment of hypertension and angina, interferes with the reproductive function of male rats. Amlodipine treatment (0.04 mg amlodipine besylate/rat/day for 30 days) decreased plasma follicle-stimulating hormone and testosterone but not luteinizing hormone or prolactin concentrations (measured by double-antibody radioimmuno-assay).

Sexual behavior and fertility of male rats submitted to prolonged immobilization-induced stress.

In order to investigate whether prolonged stress interferes with the onset of sexual behavior at puberty and with fertility at adulthood, prepubertal male Wistar rats (40 days of age) were immobilized 6 h a day for 15 days (up to early puberty) or for 60 days (until sexual maturity). Pubertal stressed rats showed a two-fold increase in the latency for the first mount (probably due to repeated aversive experience in which a change of environment was always followed by immobilization) and a 2.5-fold increase in the frequency of thrusting (indicative of enhanced sexual performance).

Decreased spermatogenic and androgenic testicular functions in adult rats submitted to immobilization-induced stress from prepuberty.

We investigated whether chronic stress applied from prepuberty to full sexual maturity interferes with spermatogenic and androgenic testicular functions. Male Wistar rats (40 days old) were immobilized 6 h a day for 60 days. Following immobilization, plasma concentrations of corticosterone and prolactin increased 135% and 48%, respectively, while plasma luteinizing hormone and testosterone presented a significant decrease of 29% and 37%, respectively.

Sexual development of hypernatriophilic male rats up to puberty.

The sexual development of normonatriophilic (Normo) and hypernatriophilic (Hyper) male Wistar rats was compared from 30 to 60 days of age (N = 8-10 per group) with emphasis on the onset of puberty. Hyper rats (more than 5 ml of saline a day in a situation of free access to tap water and 1.5% NaCl) had a 20-39% body weight reduction and a 22-29% testicular growth rate decrease compared to Normo rats.

Chemical sympathectomy blocks androgen biosynthesis during prepuberty.

Twenty-one-day old male Wistar rats were injected subcutaneously with guanethidine (GUA) at doses of 5 and 10 mg kg-1 day-1 for 20 days. Animals were sacrificed by decapitation during the prepubertal (41 days of age) and early-pubertal (51 days of age) periods of sexual development. The testes were collected, frozen in liquid N2 and stored at -70 degrees C until determination of testicular progesterone (P), androstenedione (A) and testosterone (T).

Sexual development of male Wistar rats.

1. Sexual development was investigated in male Wistar rats from 22 to 97 days of age by morphometric, biochemical and radioimmunological methods. 2.

Prepubertal development of rat prostate and seminal vesicle following chemical sympathectomy with guanethidine.

1. The internal genital organs of prepubertal, 21-day old male Wistar rats were sympathectomized by ip injection of guanethidine (G), at doses of 5 mg/kg per day (N = 10) or 10 mg/kg per day (N = 10), for 20 days. Controls (N = 10) received saline.

The male reproductive organs in the chronic phase of experimental Chagas' disease.

A previous study showed amastigote forms of Trypanosoma cruzi in the sex organs of male mice 15 days after inoculation. The purpose of the present work was to investigate the sequelae occurring in the male reproductive system during a later phase of Chagas' disease. Depleted germinal epithelium and release of immature germ cells into the tubular lumen were observed in the testis of chronic chagasic mice.

Effect of low-intensity pulsed ultrasound on prepubertal rat testis.

The testes of prepubertal male rats (N = 12) aged 21 days were stimulated with low-intensity pulsed ultrasound (1.5-MHz frequency, 1-KHz repetition pulse rate, 200-microseconds pulse width, 30-V peak-to-peak amplitude and 20-mW/cm2 intensity) applied to the skin for 20 min/day for 7 days. Control rats (N = 8) were manipulated in the same manner but not submitted to ultrasound.

Effect of an LH-RH analog on cat testis and adrenal cortex function.

The LH-RH analog LH-RH-A (des-Gly10,[D-Trp6]-LH-RH ethylamide) was administered in pharmacological doses (20 micrograms/kg, sc) to adult male cats for 15 days and its effect on testis and adrenal function was determined. Daily administration of the analog promoted a 3-fold increase in plasma testosterone levels after 7 days, indicating a stimulatory effect of LH-RH-A (mean +/- SD for 6 treated cats, 1.88 +/- 0.

Saturnism in the male rat: endocrine effects.

The effect of exposure to lead on endocrine function was studied in pubertal rats treated with 1.0 g/l lead acetate (PbAc) in drinking water for 20 days (subacute group) or 9 months (chronic group) in addition to iv injections of PbAc (0.1 mg/100 g body weight) every 10 (subacute group) or 15 days (chronic group).

Pituitary-testicular axis in benznidazole-treated rats.

Benznidazole is used extensively throughout Latin America as an antiparasitic chemotherapeutic agent against chagasic infection. We have shown that rats chronically treated with 80 mg benznidazole kg-1 day-1 for 30 days present severe testicular atrophy and arrest of spermatogenesis. In the present experiments, plasma levels of testosterone (T), luteinizing hormone (LH), follicle stimulating hormone (FSH) and prolactin (Prl) were investigated in rats receiving 10, 40 and 80 mg benznidazole kg-1 day-1 for 30 days.

Histochemical and histological analysis of the Leydig cells of cats treated with a supraphysiological dose of LH-RH analog.

An LH-RH analog (des-Gly10,[D-Trp6]-LH-RH ethylamide, LH-RH A) was administered to adult male cats for 67 days (20 micrograms/kg, sc) in order to study its inhibitory effects on the structure of Leydig cells, as determined by histological and histochemical-morphometric techniques. Histological examination showed that LH-RH A promotes a decrease in the volume of the interstitial tissue. In addition, Leydig cell nuclei exhibited marked structural alterations.

Spermatogenic and steroidogenic testicular function in hypothyroid pubertal rats.

The reproductive system of immature rats is held to be more influenced by thyroid dysfunction than that of adult animals. The effect of hypothyroidism on the spermatogenic process of the rat has not been reported previously. The objective of the present study was to investigate the spermatogenic and steroidogenic functions of pubertal hypothyroid rats.

Testes alterations in pubertal benznidazole-treated rats.

To determine the side effects of benznidazole, an antiparasitic chemotherapeutic agent against chagasic infection, rats were treated with 80 mg benznidazole kg-1 day-1, p.o., for 30 days, while controls received the vehicle.

A method for estimating the concentration of spermatozoa in the rat cauda epididymidis.

A method for estimating the concentration of spermatozoa in the rat cauda epididymidis is described. Treatment of a sperm suspension with 0.05% collagenase for 20-60 min or 0.

Stage-dependent variation in the rat Sertoli cells nuclear volume.

A morphometric study was carried out to investigate stage-dependent variation in sertoli cell nuclear volume in the rat testis. sertoli cell nuclei had the largest volumes in stages IX to X of the seminiferous epithelium cycle (746 microns3), and the smallest volumes in stage XIV (624 microns3). In the remaining stages, the nuclei presented intermediate values, without significant differences.

Functional disturbance of rat sexual accessory glands in an early phase of lead intoxication.

In order to investigate the effects of chronic lead intoxication on sexual accessory glands adult male Wistar rats were poisoned by ad libitum ingestion of lead acetate at concentrations of 0.5 g/l and 1.0 g/l for 90 d.