Uterine secretory activity and histology of prepubertal female dogs in an animal model of partial ablation of endometrial glands development / Atividade secretória uterina e histologia de cadelas pré-púberes em um modelo animal de ablação parcial do desenvolvimento das glândulas uterinas

Inadequate exposure of the female reproductive system to steroids in uterine developmental periods can partially inhibit the development of endometrial glands in dogs. However, the effects of steroids on the formed glands functionality remain unknown, as well as the possible occurrence of endometrial fibrosis. This study aimed to evaluate the secretory activity of endometrial glands in prebubertal female dogs submitted to a protocol of partial ablation of the uterine adenogenesis. Sixteen females of non-specific breed were distributed into two groups; MPA (n=8), females that received applications of medroxyprogesterone acetate every 3 weeks; and C (n=8) untreated control females. Ovariohysterectomy was performed in all animals at the age of 6 months and evaluated the uterine horns by histological and histochemistry exams. The secretion intensity (degrees 1-4) was evaluated using periodic acid-Schiff (PAS) and alcian blue (AB) pH 2.5. Histological evaluation was performed using Masson's trichrome and toluidine blue. Only degree 1 and 2 marks for PAS were observed in both groups, with no difference of uterine secretion intensity between the groups regarding the degrees found. However, the MPA group revealed higher intensity of uterine secretion compared to group C (p<0.05). Staining with AB pH 2.5 also revealed only degree 1 and 2 marks in both groups, with no statistically significance between them. Masson's trichrome staining revealed no marks in the periglandular region in both groups. A higher among of mast cells was observed in the myometrial region of the uterus in both groups. Prepubertal female dogs with partial ablation of the uterine adenogenesis present minimal uterine secretory activity, absence of periglandular fibrosis and increased presence of mast cells in the myometrium compared to endometrium.(AU)

A exposição inadequada do sistema reprodutor feminino a esteróides em períodos do desenvolvimento uterino pode inibir parcialmente o desenvolvimento das glândulas endometriais em cães. Entretanto, não se conhece os efeitos dos esteróides sobre a funcionalidade das glândulas formadas, bem como a possível ocorrência de fibrose endometrial. Objetivou-se avaliar a atividade secretória das glândulas endometriais de cadelas pré-púberes submetidas a protocolo de ablação parcial da adenogênese uterina. Foram utilizadas 16 fêmeas, sem-raça-definida, distribuídas nos grupos MPA (n=8), fêmeas que receberam aplicações de acetato de medroxiprogesterona a cada 3 semanas, e C (n=8), fêmeas controle não tratadas. Aos seis meses de idade, foi realizada ovariohisterectomia em todos os animais, e avaliados os cornos uterinos pelo exame histológico e de histoquímica. Para avaliar a intensidade de secreção (graus 1-4), foram utilizadas periodic acid-Schiff e alcian blue (AB) pH 2,5. Para a avaliação histológica foram utilizados tricrômico de Masson e azul de toluidina. Apenas marcações graus 1 e 2 foram observadas para PAS em ambos os grupos, sem diferença na intensidade de secreção uterina entre grupos com relação aos graus encontrados. Entretanto, o grupo MPA apresentou maior intensidade de secreção uterina em relação ao grupo C (p<0,05). Com relação ao AB pH 2,5, em ambos os grupos também foram encontradas apenas marcações de graus 1 e 2, sem diferença estatística entre grupos. Não foram observadas marcações para a coloração de tricrômico de Masson na região periglandular, em ambos os grupos. Foi observada maior quantidade de mastócitos presentes no útero na região do miométrio, em ambos os grupos. Conclui-se que cadelas pré-púberes com ablação parcial da adenogênese uterina apresentam mínima atividade secretória uterina, ausência de fibrose periglandular e maior presença de mastócitos no miométrio em relação ao endométrio.(AU)

Uterine secretory activity and histology of prepubertal female dogs in an animal model of partial ablation of endometrial glands development / Atividade secretória uterina e histologia de cadelas pré-púberes em um modelo animal de ablação parcial do desenvolvimento das glândulas uterinas

Inadequate exposure of the female reproductive system to steroids in uterine developmental periods can partially inhibit the development of endometrial glands in dogs. However, the effects of steroids on the formed glands functionality remain unknown, as well as the possible occurrence of endometrial fibrosis. This study aimed to evaluate the secretory activity of endometrial glands in prebubertal female dogs submitted to a protocol of partial ablation of the uterine adenogenesis. Sixteen females of non-specific breed were distributed into two groups; MPA (n=8), females that received applications of medroxyprogesterone acetate every 3 weeks; and C (n=8) untreated control females. Ovariohysterectomy was performed in all animals at the age of 6 months and evaluated the uterine horns by histological and histochemistry exams. The secretion intensity (degrees 1-4) was evaluated using periodic acid-Schiff (PAS) and alcian blue (AB) pH 2.5. Histological evaluation was performed using Masson's trichrome and toluidine blue. Only degree 1 and 2 marks for PAS were observed in both groups, with no difference of uterine secretion intensity between the groups regarding the degrees found. However, the MPA group revealed higher intensity of uterine secretion compared to group C (p<0.05). Staining with AB pH 2.5 also revealed only degree 1 and 2 marks in both groups, with no statistically significance between them. Masson's trichrome staining revealed no marks in the periglandular region in both groups. A higher among of mast cells was observed in the myometrial region of the uterus in both groups. Prepubertal female dogs with partial ablation of the uterine adenogenesis present minimal uterine secretory activity, absence of periglandular fibrosis and increased presence of mast cells in the myometrium compared to endometrium.(AU)

A exposição inadequada do sistema reprodutor feminino a esteróides em períodos do desenvolvimento uterino pode inibir parcialmente o desenvolvimento das glândulas endometriais em cães. Entretanto, não se conhece os efeitos dos esteróides sobre a funcionalidade das glândulas formadas, bem como a possível ocorrência de fibrose endometrial. Objetivou-se avaliar a atividade secretória das glândulas endometriais de cadelas pré-púberes submetidas a protocolo de ablação parcial da adenogênese uterina. Foram utilizadas 16 fêmeas, sem-raça-definida, distribuídas nos grupos MPA (n=8), fêmeas que receberam aplicações de acetato de medroxiprogesterona a cada 3 semanas, e C (n=8), fêmeas controle não tratadas. Aos seis meses de idade, foi realizada ovariohisterectomia em todos os animais, e avaliados os cornos uterinos pelo exame histológico e de histoquímica. Para avaliar a intensidade de secreção (graus 1-4), foram utilizadas periodic acid-Schiff e alcian blue (AB) pH 2,5. Para a avaliação histológica foram utilizados tricrômico de Masson e azul de toluidina. Apenas marcações graus 1 e 2 foram observadas para PAS em ambos os grupos, sem diferença na intensidade de secreção uterina entre grupos com relação aos graus encontrados. Entretanto, o grupo MPA apresentou maior intensidade de secreção uterina em relação ao grupo C (p<0,05). Com relação ao AB pH 2,5, em ambos os grupos também foram encontradas apenas marcações de graus 1 e 2, sem diferença estatística entre grupos. Não foram observadas marcações para a coloração de tricrômico de Masson na região periglandular, em ambos os grupos. Foi observada maior quantidade de mastócitos presentes no útero na região do miométrio, em ambos os grupos. Conclui-se que cadelas pré-púberes com ablação parcial da adenogênese uterina apresentam mínima atividade secretória uterina, ausência de fibrose periglandular e maior presença de mastócitos no miométrio em relação ao endométrio.(AU)

Partial ablation of endometrial glands in dogs after exposure to progestin during the neonatal period

Bitches with uteri devoid of endometrial glands should be sterile, and consequently could contribute to the population control of dogs. Considering that an inadequate exposure of the female reproductive system to steroids can lead to the formation of the uterine gland knock-out (UGKO) phenotype in some species, the aim of this study was to evaluate the effect of serial applications of medroxyprogesterone acetate (MPA) from birth until the age of six months on the development of endometrial glands in bitches. For this purpose, 16 female mongrel dogs from different litters were distributed into either an MPA group (n = 8), animals treated with 10 mg kg sc (Promone-E®, Pfizer, Brasil) at 3-week intervals, from day one after birth until the age of six months, or a control group (n = 8), composed of animals that only received a 0.9% NaCl solution in place of MPA. At six months of age, ovariohysterectomy was performed and uterine horn samples were collected for histological and immunohistochemical examinations. The bitches from the MPA-treated group presented a 35% decrease in the number of endometrial glands, a larger diameter of the endometrial glands, a greater epithelial height, as well as a greater thickness of the uterine wall, endometrium, and myometrium. However, no significant differences were observed between the two groups in the expression of ER-α, ER-β, and PR on the surface epithelium and endometrial stroma. Therefore, the serial application of MPA from birth until the age of 6 months do not completely ablate the development of the endometrial glands in bitches, but impair it by 35%.

Partial ablation of endometrial glands in dogs after exposure to progestin during the neonatal period

Bitches with uteri devoid of endometrial glands should be sterile, and consequently could contribute to the population control of dogs. Considering that an inadequate exposure of the female reproductive system to steroids can lead to the formation of the uterine gland knock-out (UGKO) phenotype in some species, the aim of this study was to evaluate the effect of serial applications of medroxyprogesterone acetate (MPA) from birth until the age of six months on the development of endometrial glands in bitches. For this purpose, 16 female mongrel dogs from different litters were distributed into either an MPA group (n = 8), animals treated with 10 mg kg sc (Promone-E®, Pfizer, Brasil) at 3-week intervals, from day one after birth until the age of six months, or a control group (n = 8), composed of animals that only received a 0.9% NaCl solution in place of MPA. At six months of age, ovariohysterectomy was performed and uterine horn samples were collected for histological and immunohistochemical examinations. The bitches from the MPA-treated group presented a 35% decrease in the number of endometrial glands, a larger diameter of the endometrial glands, a greater epithelial height, as well as a greater thickness of the uterine wall, endometrium, and myometrium. However, no significant differences were observed between the two groups in the expression of ER-α, ER-β, and PR on the surface epithelium and endometrial stroma. Therefore, the serial application of MPA from birth until the age of 6 months do not completely ablate the development of the endometrial glands in bitches, but impair it by 35%.(AU)

Partial ablation of endometrial glands in dogs after exposure to progestin during the neonatal period.

Bitches with uteri devoid of endometrial glands should be sterile, and consequently could contribute to the population control of dogs. Considering that an inadequate exposure of the female reproductive system to steroids can lead to the formation of the uterine gland knock-out (UGKO) phenotype in some species, the aim of this study was to evaluate the effect of serial applications of medroxyprogesterone acetate (MPA) from birth until the age of six months on the development of endometrial glands in bitches. For this purpose, 16 female mongrel dogs from different litters were distributed into either an MPA group (n = 8), animals treated with 10 mg kg sc (Promone-E®, Pfizer, Brasil) at 3-week intervals, from day one after birth until the age of six months, or a control group (n = 8), composed of animals that only received a 0.9% NaCl solution in place of MPA. At six months of age, ovariohysterectomy was performed and uterine horn samples were collected for histological and immunohistochemical examinations. The bitches from the MPA-treated group presented a 35% decrease in the number of endometrial glands, a larger diameter of the endometrial glands, a greater epithelial height, as well as a greater thickness of the uterine wall, endometrium, and myometrium. However, no significant differences were observed between the two groups in the expression of ER-α, ER-ß, and PR on the surface epithelium and endometrial stroma. Therefore, the serial application of MPA from birth until the age of 6 months do not completely ablate the development of the endometrial glands in bitches, but impair it by 35%.

Morphological features of the uterus during postnatal development in the West African Dwarf goat (Capra hircus)

The knowledge of the age at which the West African Dwarf (WAD) goat attains puberty could be exploited to improve this breed of goat and intensify production. The objective of this study was to highlight the postnatal developmental morphology of the uterine tissues of the WAD goat from birth to 28 weeks of age. Fifty WAD goat kids were obtained and grouped into 10 groups of 5 goats per group from day old to week 28. The uterine tissues of euthanized goats were dissected out and examined grossly. Thereafter fixed uterine tissues were prepared for light microscopy and stained with haematoxylin and eosin. Histological images of the uterine tissues were captured with a moticam camera. The length and weight of the uterine horns increased significantly (P < 0.05) from birth to week 28 respectively. The uterine horn was shaped like a ram’s horn. Internally, caruncles were prominent at birth and were regularly arranged in the uterine horn but irregularly arranged in the uterine body. Caruncles were absent in the cranial one third of the uterine horns. Histologically, the uterine horn and uterine body were similar. The endometrium was very cellular at birth without any form of glandular development, while the myometrium and the stratum vasculare were ill defined. Endometrial glands were first observed at week 1. The pseudostratified columnar epithelium of the mucosa at birth changed to simple columnar by week 12. The endometrium and the myometrium were well developed by week 12. In conclusion, the uterus of WAD goat at week 12 appeared similar to the uterus of an adult WAD goat indicating that this goat probably attains puberty earlier than the five - seven months previously reported.

Morphological features of the uterus during postnatal development in the West African Dwarf goat (Capra hircus)

The knowledge of the age at which the West African Dwarf (WAD) goat attains puberty could be exploited to improve this breed of goat and intensify production. The objective of this study was to highlight the postnatal developmental morphology of the uterine tissues of the WAD goat from birth to 28 weeks of age. Fifty WAD goat kids were obtained and grouped into 10 groups of 5 goats per group from day old to week 28. The uterine tissues of euthanized goats were dissected out and examined grossly. Thereafter fixed uterine tissues were prepared for light microscopy and stained with haematoxylin and eosin. Histological images of the uterine tissues were captured with a moticam camera. The length and weight of the uterine horns increased significantly (P < 0.05) from birth to week 28 respectively. The uterine horn was shaped like a rams horn. Internally, caruncles were prominent at birth and were regularly arranged in the uterine horn but irregularly arranged in the uterine body. Caruncles were absent in the cranial one third of the uterine horns. Histologically, the uterine horn and uterine body were similar. The endometrium was very cellular at birth without any form of glandular development, while the myometrium and the stratum vasculare were ill defined. Endometrial glands were first observed at week 1. The pseudostratified columnar epithelium of the mucosa at birth changed to simple columnar by week 12. The endometrium and the myometrium were well developed by week 12. In conclusion, the uterus of WAD goat at week 12 appeared similar to the uterus of an adult WAD goat indicating that this goat probably attains puberty earlier than the five - seven months previously reported.(AU)

Análise histomorfométrica do útero na espécie canina do nascimento aos seis meses de idade / Histomorphometric analysis of the uterus in dogs from birth to six months of age

Objetivou-se caracterizar para a espécie canina o desenvolvimento histológico uterino do nascimento aos seis meses de idade. Foram analisados úteros (n=32) de animais com idades entre um e 180 dias pós-nascimento (DPN), distribuídos em oito grupos: G1-1 DPN (1 Yorkshire Terrier, 1 Poodle, 2 Sem Raça Definida (SRD)/peso médio (Pm)=190g), G2-15 DPN (2 Yorkshire Terrier e 2 SRD/Pm=354g), G3-30 DPN (1 Rottweiler, 1 Poodle, 2 SRD/Pm=985g), G4-45 DPN (1 Poodle, 3 SRD/Pm=1,1kg), G5-60 DPN (1 Yorkshire Terrier, 1 Poodle e 2 SRD/Pm=1,4kg), G6-90 DPN (4 SRD/Pm=2,8kg), G7-120 DPN (1 Poodle e 3 SRD/Pm=6,6kg) e G8-180 DPN (1 Rottweiler, 1 Poodle e 2 SRD/Pm=11kg). A análise histológica constituiu de mensurações das espessuras (µm) da parede uterina, miométrio, endométrio, assim como diâmetro (µm) e número de glândulas endometriais. A análise estatística demonstrou estabilidade e homogeneidade nas estruturas avaliadas com coeficientes de variação baixos (<10%). Observou-se: útero com um DPN: epitélio com células cúbicas simples, miométrio rudimentar, presença de perimétrio e ausência de glândulas endometriais, aos 15 DPN: desenvolvimento de estrutura primordial de formação das glândulas endometriais, dos 30 aos 45 DPN: endométrio e glândulas endometriais simples, aos 60 DPN: glândulas endometriais em lâmina própria com ramificações e discreto pregueamento endometrial, de 90 a 180 DPN: todas as estruturas uterinas apresentaram histoarquitetura de um animal maduro. Todas as variáveis analisadas apresentaram correlação positiva com a idade pós-nascimento (R272,2%). Conclui-se que o útero da cadela desenvolve-se continuamente do nascimento à 180 dias de vida e que apresenta-se desprovido de glândulas endometriais ao nascimento. As primeiras glândulas endometriais são observadas aos 15 dias de vida e apresenta conformação histológica de um animal adulto após 60 dias do nascimento.(AU)

This study aimed to characterize canine species' uterine histological development from birth to six months of age. Uteri (n = 32) of animals aged between one and 180 days postnatal (PND), distributed into eight groups were analyzed: G1-1 PND (1 Yorkshire Terrier, Poodle 1, 2 Mixed Breed (MB)/Medium weight (Mw) = 190g), G2-15 PND (2 Yorkshire Terrier and 2 MB/Mw = 354g), G3-30 PND (1 Rottweiler, 1 Poodle, 2 MB/Mw = 985g), G4-45 PND (1 Poodle, 3 MB/Mw = 1.1kg), G5-60 PND (1 Yorkshire Terrier, Poodle 1 and 2 MB/Mw = 1.4kg), G6-90 PND (4 MB/Mw = 2.8kg), G7-120 PND (1 Poodle and 3 MB/Mw = 6.6kg) and G8-180 PND (1 Rottweiler, Poodle 1 and 2 MB/Mw = 11kg). Histological examination consisted of thickness measurement (µm) of the uterine wall, myometrium, endometrium, as well as diameter (µm) and number of endometrial glands. Statistical analysis showed stability and uniformity in the evaluated structures with low coefficients of variation (<10%). We observed: uterus with one PND: simple cubic epithelium cells, rudimentary myometrium, perimetrium presence and absence of endometrial glands, at 15 PND: development of primordial structure formation of endometrial glands, from 30 to 45 PND: simple endometrium and endometrial glands, PND 60: endometrial glands in the lamina propria with branches and discreet endometrial pleating, 90-180 PND: uterine all structures presented histoarchitecture of a mature animal. All variables were positively correlated with postnatal age (R2 72.2%). It is concluded that the uterus of the bitch continuously evolves from birth to 180 days old and is presented devoid of endometrial glands at birth. The first endometrial glands are observed at 15 days of life and present histological conformation to an adult 60 days after birth.(AU)

Análise histomorfométrica do útero na espécie canina do nascimento aos seis meses de idade / Histomorphometric analysis of the uterus in dogs from birth to six months of age

Objetivou-se caracterizar para a espécie canina o desenvolvimento histológico uterino do nascimento aos seis meses de idade. Foram analisados úteros (n=32) de animais com idades entre um e 180 dias pós-nascimento (DPN), distribuídos em oito grupos: G1-1 DPN (1 Yorkshire Terrier, 1 Poodle, 2 Sem Raça Definida (SRD)/peso médio (Pm)=190g), G2-15 DPN (2 Yorkshire Terrier e 2 SRD/Pm=354g), G3-30 DPN (1 Rottweiler, 1 Poodle, 2 SRD/Pm=985g), G4-45 DPN (1 Poodle, 3 SRD/Pm=1,1kg), G5-60 DPN (1 Yorkshire Terrier, 1 Poodle e 2 SRD/Pm=1,4kg), G6-90 DPN (4 SRD/Pm=2,8kg), G7-120 DPN (1 Poodle e 3 SRD/Pm=6,6kg) e G8-180 DPN (1 Rottweiler, 1 Poodle e 2 SRD/Pm=11kg). A análise histológica constituiu de mensurações das espessuras (µm) da parede uterina, miométrio, endométrio, assim como diâmetro (µm) e número de glândulas endometriais. A análise estatística demonstrou estabilidade e homogeneidade nas estruturas avaliadas com coeficientes de variação baixos (<10%). Observou-se: útero com um DPN: epitélio com células cúbicas simples, miométrio rudimentar, presença de perimétrio e ausência de glândulas endometriais; aos 15 DPN: desenvolvimento de estrutura primordial de formação das glândulas endometriais; dos 30 aos 45 DPN: endométrio e glândulas endometriais simples; aos 60 DPN: glândulas endometriais em lâmina própria com ramificações e discreto pregueamento endometrial; de 90 a 180 DPN: todas as estruturas uterinas apresentaram histoarquitetura de um animal maduro. Todas as variáveis analisadas apresentaram correlação positiva com a idade pós-nascimento (R2≥72,2%). Conclui-se que o útero da cadela desenvolve-se continuamente do nascimento à 180 dias de vida e que apresenta-se desprovido de glândulas endometriais ao nascimento. As primeiras glândulas endometriais são observadas aos 15 dias de vida e apresenta conformação histológica de um animal adulto após 60 dias do nascimento.

This study aimed to characterize canine species' uterine histological development from birth to six months of age. Uteri (n = 32) of animals aged between one and 180 days postnatal (PND), distributed into eight groups were analyzed: G1-1 PND (1 Yorkshire Terrier, Poodle 1, 2 Mixed Breed (MB)/Medium weight (Mw) = 190g), G2-15 PND (2 Yorkshire Terrier and 2 MB/Mw = 354g), G3-30 PND (1 Rottweiler, 1 Poodle, 2 MB/Mw = 985g), G4-45 PND (1 Poodle, 3 MB/Mw = 1.1kg), G5-60 PND (1 Yorkshire Terrier, Poodle 1 and 2 MB/Mw = 1.4kg), G6-90 PND (4 MB/Mw = 2.8kg), G7-120 PND (1 Poodle and 3 MB/Mw = 6.6kg) and G8-180 PND (1 Rottweiler, Poodle 1 and 2 MB/Mw = 11kg). Histological examination consisted of thickness measurement (µm) of the uterine wall, myometrium, endometrium, as well as diameter (µm) and number of endometrial glands. Statistical analysis showed stability and uniformity in the evaluated structures with low coefficients of variation (<10%). We observed: uterus with one PND: simple cubic epithelium cells, rudimentary myometrium, perimetrium presence and absence of endometrial glands; at 15 PND: development of primordial structure formation of endometrial glands; from 30 to 45 PND: simple endometrium and endometrial glands; PND 60: endometrial glands in the lamina propria with branches and discreet endometrial pleating; 90-180 PND: uterine all structures presented histoarchitecture of a mature animal. All variables were positively correlated with postnatal age (R2 ≥ 72.2%). It is concluded that the uterus of the bitch continuously evolves from birth to 180 days old and is presented devoid of endometrial glands at birth. The first endometrial glands are observed at 15 days of life and present histological conformation to an adult 60 days after birth.