Gaddi sheep is the important breed of Himachal Pradesh, used for fine carpet wool and meat production. A very little work has been done on the histochemistry of the lung of Gaddi sheep. Therefore, present investigation was planned to demonstrate the histochemical activity of glycogen, basic protein and fat in prenatal Gaddi sheep lung which can be used for further investigation and forms basis of further research.

Mills et al. (1986) observed that the bronchial epithelium generally showed moderate reactions to carbohydrates in pigs. However, the goblet cells showed mild reaction.

Baba et al. (2013)studied the histochemistry of carbohydrates and proteins in the pulmonary bronchi of Black Bengal goat (Capra hircus) and found that the goblet cells, glands, cartilage and perichondrium manifested intense positive reaction for carbohydrates whereas, connective tissues, muscle fibres and blood vessels showed generally weak to moderate positive reactions. The bronchial epithelium, glands, cartilage, matrix and muscle layers manifested strong reactions for acid mucopolysaccharides. Reaction for proteins was strong to intense in the bronchial epithelium, glands, perichondrium of bronchial cartilage and muscle fibres. Vikas (2015) conducted studies on prenatal goat fetuses and reported that a weak activity of glycogen, basic proteins, neutral and acidic mucopolysaccharides was observed in group I. The basement membranes were reported to be moderately glycogen and basic protein positive. A weak activity for basic proteins was observed in walls of blood vessels.

Materials and Methods                                                 

For present investigation (n=18) Gaddi sheep fetuses were collected from the slaughter houses in and around Palampur region and were then divided into three groups based on their estimated ages viz. Group-I (below 50 days), Group-II (between 50-100 days) and Group-III (above 100 days of age) containing 6 number of fetuses in each group. The age was obtained by the formula, W⅓=0.096 (t-30) Singh et al. (1979), where, W is body weight of fetus in g, t is age of fetus in days. The lung was infused by intra tracheal instillation of 10% neutral buffered formalin solution (Luna, 1968) until it was inflated (of life size), then ligated on the trachea and immersed in the same fixative in a container for proper fixation (Drury and Wallington, 1980). Tissue pieces were collected from apical, cardiac, diaphragmatic and intermediate lobes of the fixed lungs of the sheep fetuses. These tissues were processed for paraffin block preparation by alcohol- benzene schedule (Luna, 1968). Tissue sections of 5-6 µm were obtained from these blocks on clean glass slides with the help of rotary mictrotome. The sections were then subjected to Best Carmine method for glycogen, Sudan Black B method for fat (Luna, 1968) and Bromophenol Blue method for proteins (Pearse, 1972).

Statistical Methods

No statistical method was used for the present study.

Results and Discussion

Glycogen

In Group-I there was a moderate reaction for glycogen in the mesenchyme, basement membrane of bronchiolar epithelium and blood vessels (Plate 1), whereas the basement membrane of tubule and capsule were moderately to strongly reactive for glycogen. In Group-II a moderate activity was observed for glycogen in parenchyma, basement membrane of bronchiole, wall of blood vessel (Plate 2), but a weak reaction was observed in the capsule. The epithelium of bronchi and alveoli showed moderate amount of glycogen (Plate 3). A moderate reactivity to glycogen was seen in (Table 1). Mills et al. (1986) observed that the bronchial epithelium generally showed moderate reactions to carbohydrates in pigs. In contrast, Suman et al. (2005) observed a weak reaction for carbohydrates in respiratory bronchiole in post natal lung in goat.

Table 1: Reaction exhibited by tissue components for glycogen

– Absent, + weak, ++ moderate, +++ strong, ++++ intense, NA not found

Basic Protein

In group-I strong reactivity for basic proteins was observed in basement membrane of tubule (Plate 4) and bronchiole. However, a moderate reaction was observed in the mesenchyme and capsular region.

Table 2: Reaction exhibited by tissue components for basic protein

– Absent, + weak, ++ moderate, +++ strong, ++++ intense, NA not found

A moderate reaction was observed in cartilage, trabeculae, blood vessel wall, basement membrane of bronchi and parenchyma of the lung tissue in group-II (Plate 6). Whereas, the basement membrane of bronchiole (Plate 5) and capsule showed strong reactivity for basic proteins. In group-III a moderate reactivity was observed in cartilage, capsule, trabecular region of the lung tissue. While a strong reaction in alveoli, wall of blood vessel, basement membrane of bronchi & bronchiole was observed (Plate 7).

In group-III strong reactions to basic protein was observed in the cytoplasm of the lining epithelium of the developing airways (Table 2). Baba et al. (2013) reported that the cytoplasm of the lining epithelium of the developing airways showed strong reactions to basic proteins. Similar observation was found in group-III.

Fat

The fat content was not observed in the lungs of fetuses in group I and II. However a weak reaction to fat was observed in group-III around the basement membrane of bronchioles and internal lamina of blood vessels (Plate 8).

Acknowledgement

To the department of Veterinary Anatomy, DGCN College of Veterinary and Animal Sciences, Chaudhary Sarwan Kumar Himachal Pradesh Krishi Vishvavidyalaya, Himachal Pradesh (India).

Conclusion

References

1. Baba, M.A., Choudhury, A.R. and Khan M. (2013). Histochemical studies of carbohydrates and proteins in the pulmonary bronchi of Black Bengal goat (Capra hircus).Indian Journal of Veterinary Anatomy, 25(2):102-104.
2. Drury, R.A.B. and Wallington, E.A. (1980).Carleton’s Histological Technique. 5^th, Oxford University Press, Oxford.
3. Luna, L.G. (1968). Manual of histological staining methods of Armed forces institute of Pathology. 3^rd . McGraw Hill Book Company, New York. pp. 153-173.
4. Mills, A.N., Lopez-Vidriero, M.T. and Haworth, S.G. (1986). Development of the airway epithelium and submucosal glands in the pig lung: changes in the epithelium glycoprotein profiles. British Journal of Experimental Pathology, 67: 821-829.
5. Pearse, A.G.E. (1872). Histochemistry: Theoretical and Applied. 3^rd Churchill, Livingstone, London. pp 607.
6. Singh, H., Sharma, D.N. and Dhingra, L.D. (1979). Morphogenesis of testis in goat. Indian Journal of Animal Sciences 49: 925-931.
7. Suman, Gupta, A.N. and Jain, R.K. (2005). Histomorphology and histochemistry of respiratory bronchiole during postnatal development of lungs in goat. Haryana Veterinarian, 44: 55-59.
8. Vikas, S. (2015). Anatomical studies on prenatal development of the lung in goat (Capra hircus). M. V. Sc. Thesis. Division of veterinary anatomy. Sher-e-Kashmir University of Agricultural Sciences and Technology, Jammu, India.