ABSTRACT. We dissected the hindlimb of a female western lowland gorilla and determined the muscle dimensions (mass, fascicle length, and physiological cross-sectional area: PCSA). Comparisons of the muscle parameters of the measured gorilla with corresponding reported human data demonstrated that the triceps surae muscles were larger and had more capacity to generate force than the other muscle groups in both species, but this tendency was more prominent in the human, probably as an adaptation to strong toe-off during bipedal walking. On the other hand, PCSAs of the extrinsic pedal digital flexors and digiti minimi muscles were larger in the western lowland gorilla, suggesting that the foot, particularly the fifth toe, has a relatively high grasping capability in the lowland gorilla.KEY WORDS: foot, gorilla, muscle architecture.J. Vet. Med. Sci. 71(6): 821-824, 2009 Gorillas are generally regarded as the most terrestrial of the extant hominoids. However, the degree of arboreality is known to vary among subspecies. Mountain gorillas (G. gorilla beringei) living in eastern central Africa seem to be the least arboreal, and the amount of time they spend above ground is only 7% in females and 2% in males [1]. On the other hand, western lowland gorillas (G. g. gorilla) in western central Africa are observed to be more arboreal and are frequently found in trees higher than 20 m [1,9]. Such differences in the degree of arboreality among the subspecies are correlated with foot anatomy. The foot of the western lowland gorilla has a relatively longer free portion of the first toe capable of opposing to the other four toes for grasping, whereas that of the mountain gorilla is relatively more humanlike and adapted for terrestrial locomotion [10,11].Therefore, understanding subspecies variations in the muscular characteristics of the gorilla foot is important for interpreting functional adaptations of the foot in hominoids. However, although Payne et al. [8] have reported the muscle architecture of the gorilla's hindlimb, no studies so far have provided complete quantitative data on all of the foot muscles, including the intrinsic muscles.In this study, we dissected the left hindlimb of a female western lowland gorilla to provide complete quantitative * CORRESPONDENCE TO: OISHI, M., First Department of Anatomy, School of Veterinary Medicine, Azabu University, 1-17-71, Fuchinobe, Sagamihara, Kanagawa 229-8501, Japan. e-mail: dv0502@azabu-u.ac.jp Tables 1 and 2.

Summary Cytosolic and secretory carbonic anhydrase isoenzymes (CA‐II and CA‐VI, respectively) were detected by immunohistolocalization using specific canine CA‐II and CA‐VI antisera. CA‐II and CA‐VI were identified in glands associated with the canine lacrimal apparatus, such as lacrimal gland, superficial gland of the third eyelid (third eyelid gland) and tarsal gland. CA‐II and CA‐VI mRNA signals were also detected by reverse‐transcriptase polymerase chain reaction in the same tissues. Some serous acinar cells and duct segments in the lacrimal gland and serous acinar cells in the third eyelid gland were immunopositive for anti‐CA‐II and CA‐VI antisera. In particular, some immunopositive acini to CA‐II and CA‐VI on the edge of the third eyelid gland are histologically similar to sebaceous gland cells. Sebaceous gland cells in the tarsal and ciliary glands also showed immunopositivity to both CA antisera. CA‐II and CA‐VI gene transcripts were detected in the same regions. These results suggest that secreted CA‐VI may form together with cytosolic CA‐II, a high‐activity isozyme mostly considered as a bicarbonate producer, in a mutually complementary system for the maintenance of bicarbonate levels to regulate pH in tear fluid and protect the corneal epithelia against injuries. In sebaceous gland cells in the lacrimal apparatus, CA‐VI may be related to lipogenesis in an unknown function.

ABSTRACT. Immunolocalization of the secretory form of carbonic anhydrase isoenzyme, CA-VI were studied using a specific canine CA-VI antiserum, and CA-VI mRNA signals were also investigated using the reverse-transcriptase polymerase chain reaction (RT-PCR) in canine nasal mucosal epithelia and glands. Immunoreactivity to CA-VI was positive throughout the mucosal epithelial cells and in the cytoplasm of serous acinar and ductal epithelial cells of the nasal mucosa and glands, including the vestibule of the nose, but the mucous acinar cells of the glands were immunonegative. We detected CA-VI gene transcripts in the same regions as the CA-VI immunoreactivity. The physiological roles of CA-VI in the nasal mucosal epithelium and glands might maintain bicarbonate levels in nasal secretions and protect the mucosa against acid. KEY WORDS: canine nasal cavity, CA-VI, immunohistochemistry, mRNA.

ABSTRACT. The immunohistolocalization and gene expression of carbonic anhydrase (CA) isoenzymes CA-II and CA-VI in the canine lower airways and lung were examined using specific canine CA-II and CA-VI antisera and the RT-PCR method. Laryngeal, tracheal and bronchial epithelia, serous acinar and bronchiolar secretory cells and pulmonary great alveolar cells showed immunopositive reactions to anti-CA-II and anti-CA-VI antisera. However, all mucous cells showed immunonegative reactions. The physiological roles of CA-II and CA-VI in the lower airways and lung may involve the maintenance of pH balance and the protection of mucosal surfaces against the acidic milieu.KEY WORDS: canine respiratory tract, carbonic anhydrase, immunohistochemistry, RT-PCR.