Capillary supply of the muscle fibre population in hindlimb muscles of the cat

Abstract

Comparative analyses of the fibre content (FG, FOG, and SO fibres) and the capillary density (the number of capillaries surrounding individual fibres and the capillary/fibre ratio) were performed in hind limb muscles of the cat. Cross-sections from the tenuissimus, the biceps femoris, the lateral head (LG) and the medial head (MG) of the gastrocnemius and the soleus were cut in a cryostat. The sections were stained histochemically for the NADH2-diaphorase and alkaline (pH 9.4) actomyosin ATPase activity, which enables differentiation of different types of fibres. The endothelium of the capillaries was identified via staining for unspecific alkaline ATPase activity. The number of capillaries surrounding each individual muscle fibre had a positive correlation, first to the oxidative capacity and secondly to the average diameter of the fibres. The thin tenuissimus muscle did not differ in this respect from the thicker muscles. The highest proportion of SO fibres was found in the soleus and the MG muscles. FG fibres of two different types were dominating the fibre mass in the biceps femoris and the LG muscles, while the tenuissimus contained more FOG fibres than these muscles. In general the FG fibres had a larger diameter than the FOG and the SO fibres. The soleus and the MG muscles contained larger fibres than the other examined muscles. FG fibres were surrounded by fewer capillaries than FOG and SO fibres. The soleus and the MG muscles, with a higher percentage of SO fibres and also larger fibres, had the largest number of capillaries around the fibres and the highest capillary/fibre ratio.

Somatic and intramuscular distribution of muscle spindles and their relation to muscular angiotypes

“…Thus, soleus has a higher capillary number per mm 2 of cross sectional area, a higher capillary to fiber ratio, and a higher number of capillaries around a single fiber, compared to lateral gastrocnemius and the superficial portion of the medial gastrocnemius. As Table 1 reveals, however, vascular differences between Myrhage (1978) and Myrhage and Eriksson (1980). SO: slow oxidative; FOG: fast oxidative-glycolytic; FG: fast glycolytic.…”

“…Barker, 1962), a denser capillarity compared to glycolytic areas (e.g. Romanul, 1964;Mai et al, 1970;Plyley and Groom, 1975;Myrhage, 1978;Myrhage and Eriksson, 1980;Gray et al, 1983;Stephens, 1985;Ovalle et al, 1999;Suzuki et al, 2000), a richer oxygen consumption (Adair et al, 1990), a higher density of mitochondria (Hoppeler and Kayar, 1988), a higher number of action potentials reaching them per day (Brown et al, 1976;Hennig and L . omo, 1985;Gordon and Patullo, 1993), a lack of NO synthase-1 (present only in glycolytic fibers, Lincoln and Harb, 1998), etc.…”

“…Examples of ''angiotypic'' variations found in mammalian muscles are summarized in Table 1, based on the data from the cat soleus and gastrocnemius (Myrhage, 1978;Myrhage and Eriksson, 1980). According to these data, the vascular arrangement in skeletal muscles is modular, i.e.…”

Effects of hindlimb suspension and reloading on gastrocnemius and soleus muscle mass and function in geriatric mice

“…Indeed, satellite cell proliferation which is required during muscle repair and may be important in muscle recovery after disuse (Alway, et al 2017b; Alway, et al 2011; Alway, et al 2014c; Alway, et al 2013; Brooks, et al 2018), is greater in fibers with a high capillarity to fiber ratio (Joanisse, et al 2018; Nederveen, et al 2018). Thus, it is possible that refraction of capillarity and therefore blood flow during unloading (Desplanches, et al 1990; Hirayama, et al 2017) is reversed during reloading, especially in the soleus fibers, which have greater capillarity than the gastrocnemius muscle fibers (Myrhage 1978). The dissimilar responses in type I fibers in the gastrocnemius and soleus muscles might be the result of non-uniform changes in vascularity throughout skeletal muscle arteriolar networks between soleus and gastrocnemius fibers (Laughlin and Roseguini 2008) leading to different potentials for the type I fibers in gastrocnemius and soleus muscles to receive humoral anabolic compounds (e.g., myokines) during reloading.…”

Morphological Studies on Skeletal Muscle Capillaries Under Conditions of High Altitude Training*

“…The capillary supply of skeletal muscle is an important factor for aerobic work power (24). It is correlated to the amount of red (oxidative) muscle fibers since these fibers are generally supplied by more capillaries than white fibers (15,22,32,34,37,44). Moreover, red muscles are described as containing a peculiar capillary pattern that is characterized by mostly tortuous capillaries (42,43,46).…”