Neutrophil Granules of Red Seabream Pagrus major Infected with Lamellodiscosis

ラメロジスカス症に罹患したマダイの好中球顆粒

Neutrophil Granules of Red Seabream Pagrus major Infected with Lamellodiscosis

Creators Kondo Masakazu

Creators Yasumoto Shinya

Two types of chromophobic granules [type 1, ordinary type (oβG-1^{Ld})； type 2, extraordinary type (eoβG-2^{Ld})] were observed in the neutrophils of red seabream Pagrus major infected with Lamellodiscus spp. The oβG-1^{Ld} showed similar morphology and cytochemistry to type 1 ordinary chromophobic granule (oβG-1) from non-infected fish: Chromophobic, simple morphology (without stratified structure), positive reaction to peroxidase (PO) and Sudan black B (SBB), and lack of lysozomal enzymes. The eoβG-2^{Ld} was stratified granule with two-layer structure [inner eosinophilic layer (L0) and outer chromophobic layer (L1)]. Several lysozomal enzymes [acid phosphatase (AcP), β-glucuronidase, α-naphtyl acetate esterase, α-naphtyl butyrate esterase, naphthol AS-D chloroacetate exterase (CAE)] were detected in the L0, however, AcP and CAE were localized in the small central area of L0. These findings indicate that the L0 of eoβG-2^{Ld} consists of L0-0 (inner part in L0； AcP and CAE positive) and L0-1 (outer part of L0-0). The L1 showed positive reaction to SBB and PO. Spot formation, a curious phenomenon appeared in PO-stained type 2 ordinary chromophobic granule (oβG-2； positive L1 and negative L0) from non-infected fish, was not observed in eoβG-2^{Ld}.

[ISSN]0370-9361